Chinese Mains Transformer QC also non-existent.

Another piss-and-vinegar post from me.  In the last post I alluded to the fact that I was having mains transformer issues with my RCT builds.  Here, I'll air my grievances.

More than a year ago, after having decided to construct two more remote switches, I quickly made a list of the parts required and shot off half a dozen orders to Ebay.  One thing I could not source on Ebay was the needed mains transformers, which was the reason that, despite proclamations in earlier posts, I ended up going back to Aliexpress, tail firmly between legs.  Although Ebay would be nothing without Asian Sellers, many more of these Sellers only seem to sell their wares through Aliexpress.  Anyway, transformers were ordered and promptly delivered.

Only, I had ordered the wrong ones!  At the time, I took a quick look inside my one remote switch, had seen 6v written on the transformer, so ordered two of the 220v @ 6v variety.  Only many months on, when I had finally received the PCB's from JLCPCB, and had started building, did I realise that what I needed was 12v transformers, not 6v, to power the 12v relays, and that the transformer in my working unit was in fact supplying 12v - 3-wire 6v-0v-6v.  Duh!  Unperturbed, I went a-searching on Aliexpress, found the correct transformers, or more accurately, the same spec 220v @ 6v-0v-6v transformers used in my working unit, but at less than half the price of what I had paid first time round, so shot off another order.  These also arrived quickly and seemed fine apart from the fact that there was adhesive all over the wires, probably that used to secure the iron core laminations, plus said leads were a little shorter than I would have liked.  But hey, I'd gotten them for half the price, so no biggie.

On connecting one up to my build under construction, what immediately became apparent was that, although they 'worked', you could hear that the 12v relay was being switched 'hard-on'.  Measuring the voltage across it while energised, I was shocked to see that it was over 18v DC.  De-energised, that rose to almost 20v.   The voltage across the 6v - 6v wires of the secondary was 16.4v AC, not the 12v AC that I was expecting.  Note that this is on a 240v mains supply, nominally around 238v, though the extra volts don't significantly change things.

I wasn't happy with this in the least, even after I realised that the relay would happily trigger when I used the 6v - 0v wires, therefore working from just 8.6v DC, I concluded that the 'cheapness' of the transformers was the culprit.  Particularly after checking the first 220v @ 6v transformers purchased and finding that they provided a reasonable 6.5v AC on their secondaries.  So, back to Aliexpress I go and order another 2 'expensive' transformers from the original seller, this time, 220v @12v, 2-wire, in the fervent hope that these would provide the expected voltage.

They didn't, and I'm pissed!!!

Below are a series of pics taken of measurements from the various transformers in play.  To be as unbiased as possible, I am powering them from a variac, supplying 220v AC.

 

 
Below are the voltage measurements taken from the working unit, but with the transformer in-circuit.  The first shows it being supplied from the variac @ 220v AC. The circuit is being powered (@ 15mA's), though the relay is not energised.  The secondary of the transformer sits at 11.47v AC.

Here I adjust the variac to provide 240v to the circuit.  The voltage increases to 12.27v AC, which had me wondering if these particular transformers, bought from Maplin (RIP) almost 30 years ago, were specifically manufactured in/for the UK.  Regardless, these are the voltages I expect to see from a 12v transformer, not some 3+ volts over the stated RMS value.

Finally, Also shown below are measurements across the transformer's secondary with the relay powered on & off, to show loading effects.  The maximum current drawn from the secondary by the PCB is 75mA AC.

Edit1:
Been playing with my scope's Save/Recall function, and aided by Linux's ever-versatile Gimp, grabbed waveforms & measurements from the 3 offending transformers, on the mains supply, and shown below.

Edit2:
Given the lottery that seems to be involved when buying transformers from China, I instead decided to try dismantling one of the 220v @ 12v 2-wire ones, to see how difficult it would be to adjust the turns-ratio of its secondary.  I had low hopes going into this - I figured there was a 70% chance of screwing it up entirely - instead, it proved to be surprisingly easy!

This was the first transformer I'd taken apart in this manner.  The wire to be removed from the secondary I calculated as follows;

19 Ohms (actual secondary resistance) - 12v (desired volts)  / 14.98v (actual volts) * 19 Ohms = 3.76 Ohms.

This is the resistance of the wire segment that needed to be removed.  I then used this Round Wire Resistance Calculator site to determine the length of (0.17mm) wire that would have a resistance of 3.76 Ohms - turned out to be a little over 5 meters.  After removing this amount and reassembling, I was pleased to find that its voltage after rectification, with the relay de-energised, had dropped to a much 'safer' level of 15.9v, one that wouldn't pop my 16v 220uF reservoir capacitor over time - the voltage had been over 19v in the 'relay-off' state.

However, the values I had used in the above calculations had been with a 220v supply, not the 240v I will actually be using.  So, working on the second 220v @ 12v transformer, and re-doing the above calculation with 15.8v as the 'actual volts', gave me a 'wire length to be removed'  of 6.175 meters. After doing so, i was presented with an RMS value of just over 13v AC on the secondary, which, in-circuit, rises to no more than 15.1v DC.  With the relay engaged, it actually drops to around 11.5v DC.  So, yay, I'm happy with this result.

Hozan: Manufacturer of True 'Precision' Tools...

I bought my first 'proper' workbench tools over 30 years ago, a snips/cutters and a Snipe-nosed pliers, from Cricklewood Electronics, made by the prestigious German toolmaker C.K.  They cost a little over £10 each, way back then.  Despite the decades of abuse, these performed admirably, or at least one of them did - the first snips I destroyed within a few years, trying to cut something way beyond its pay-grade.  Lesson learnt, I immediately went out and bought another, and it's still in use today.  The original pliers, withstood three decades of similar abuse, but recently, heedless of past misdeeds, and being employed in a really dumb task, I managed to break this as well.  I was distraught.

But looking to get back on the horse as quickly as possible, I went searching for a replacement, and was elated to discover that Amazon sells the exact same pliers, though costing considerably more - almost £27 then, though the price continues its upward spiral, it currently costs £33.  But I was content to pay a premium for a tool of this quality.

Until receiving it anyway!  Examining it, it was immediately apparent that, in my opinion, the "C.K Classic T3772 120mm 'Precision' Snipe Nose Pliers", did not live up to this description.  I would have thought that the workmanship of tools made today would at least meet the standards of those produced by the same manufacturer more than 30 years ago - apparently not!  Although the jaws themselves were fine, where the two pieces hinge, there were large gaps, more than 1mm in places, and on both sides.  A side-by-side comparison with its much older (and broken!) sibling, highlights this (see pics).

 

Though some might accuse me of being pedantic, this was not acceptable to me, so back it went to Amazon.  I hoped my negative review about it on the site would at least have garnered a response from a C.K Rep, as C.K themselves are the Seller, but it was not to be.  Apparently, this level of 'Precision' is now the accepted norm in Germany.

All of this transpired back in February, so over 6 months ago, and I was still without a proper pliers for my bench-work.  So it was time to go shopping again, but this time I thought I'd give Ebay a try.

On searching, it became clear early on, that the Japanese company Hozan was one of the main contenders where quality tools were concerned, to the point that many Sellers, reassuringly all Japanese, post pics on how to spot forgeries.  One of these tell-tale signs was precisely the reason I returned the C.K pliers - poor manufacturing tolerances at the hinge-point.

Although I really only needed a pliers, as the C.K side-cutters is now quite blunt, I figured I may as well treat myself to a new snips as well.  Then I went completely mad and bought another, much more expensive, 'pulling-pliers' - or at least that was its intended use, to facilitate the removal of say, 8 to 14 pin i.c's.  Turns out the 'pliers' is actually a cutters and too small for extracting anything above 8-pin i.c's anyway, so it probably won't see much use.  All told, these cost $21 (snips), $27 (pliers) and $37 ('pulling' pliers) respectively.  See pics.

But, and the main point here, all of their 'tolerances'  are superb!  The fact that they are all 'spring-opened', rather than using a leaf-spring like the C.K tools, is a bonus in my eyes.  This is what I expect to see from quality 'Precision' tools.

So despite my having had a long history with C.K of Germany, I have reluctantly had to switch to a manufacturer that seems to care about the quality of the tools that they manufacture.  In my eyes, Hozan fits the bill on this count.  It's just a  shame that a long-established company like C.K seems to have become complacent with the passing of time.

Chinese BC108B Transistors (TO-18): non-existent QC in play...

As part of my 'RCT Revamp'. I've been slowly accumulating the bits needed to build two more Remote Switches, to complement the single unit that I had originally built.  But that's for another post, this is about the BC108B transistors needed that I sourced & bought through Aliexpress - and yes, I'm back buying stuff from this lot again!

After getting my PCB's from JLCPCB - so much easier than messing with ferric chloride, like I did originally! - I soon had one (1 of 5) populated & ready to rock.  Except it didn't work!  Checking the 6 BC108B transistors with a multimeter, I discovered that one was completely open - all B-C-E connections, which seemed decidedly odd.  All the others tested fine.  Swapping out the dud with a new one didn't solve the problem.  I then went off on the wrong tack and ended up destroying two UM3750's, the decoder chip used, which apparently are really finicky about the voltage level applied to its input.

Long story short, with my one working (old) unit to compare against, it soon became apparent that there was something amiss with the transistors I was using.  Starting afresh with a new PCB (2 of 5), and taking measurements as I built, I soon realised that the transistors were not 'amplifying'  the superimposed 200Khz signal from the mains.  Removing all four that I had soldered in, and checking their gain with my trusty old meter, I was shocked to discover that their gain (hFE) ranged between 0 to 107, far from the 200 minimum that these transistors are rated at.  The last two unused transistors were also checked, these came in at 84 and 102 respectively (see pics).

This got me to wondering about the 100+ other Chinese transistors that I've got, which are all of the TO-92 variety.  These as it happens, seem to be perfect, each batch of the same transistors measuring respectable hFE's, and within shouting distance of their compatriots.

So it seems that only the TO-18 type BC108B's that I've bought are crap.  And they were not particularly cheap either!  The reason I ended up ordering them from Aliexpress was that they are considerably more expensive when ordered from Ebay sellers.  But what I got is garbage, which is compounded by the fact that I ordered another 20 of them (from a different Aliexpress seller) [after checking, it's actually an Ebay Seller] before I discovered the hFE problem.

It would appear incredibly unlikely that the 'ST' branded BC108B's  that I got are actually manufactured by STMicroelectronics, instead being produced by some knock-off outfit that employs zero Quality Control testing.

I've being playing with transistors for 40+ years and admit that I had never before come across a transistor with zero gain.  Or 32 for that matter.  Out of the 15 transistors I ordered, only 2 came close to the expected 200 gain (213 & 187).  These two can be seen soldered in-situ and that portion of the circuit (now) works as expected.
 
Edit:
I removed all six BC108B transistors from the first PCB (1 of 5) today, to check their gain.  As expected, the highest gain measured was 102, with one coming in at a mere 10 - so, it's understandable that this RCT build wasn't working!  I figured though that the one 102-gain transistor would work ok in what I deemed a 'non-critical' part of the circuit - wrong!  Removing it again and replacing it with a 187-gain TO-92 transistor, had the circuit working perfectly.

Now all I need to do is triple-check the changes I have made to the PCB layout and re-submit them to JLCPCB.  Although the original batch (of 5) work fine, given how cheap they were, I didn't bother adding mounting-holes first time round, as I was sure that there would be other issues that would be discovered during the build-process - there were, but mainly minor things like component placement & hole-sizes, that need altering.  I am also taking the opportunity to add a single component of my own to the circuit, a 5.1v zener diode, to squish a nasty transient spike, on one of the 'SET' pins of the 74LS74, which is generated during switching, and only discovered today.  Even though it spikes to almost 9v, so well above the 5v operating voltage, the original RCT unit's 74LS74, suffering from the same condition, [maybe not... after checking, it spikes, but less than a volt, odd...] is still working after nearly 25 years, so yeah, a non-critical addition.  But on the off-chance that it might cause occasional false-triggering, I may as well fix the problem.  

Edit1:

Update.  Just received my new order of 20 BC108B's.  Testing, first four out of the bag had me questioning my new-found beliefs about Chinese QC - all 4 had an hFE >= 200 - unfortunately, this run of luck was not to continue.  All told, 10 proved to have gains greater than 200, 4 were less than 170, 3 less than 100 and another 3 less than 50.  A crap-shoot basically!  Even the hFE > 200 varied wildly, with gains ranging between 200 and 700, although admittedly, most were around 200.  So I guess it's up to the buyer of cheap tat like this, to first test, then keep the best & bin the rest.

Luckily, I've now got enough BC108B's of the TO-18 variety to populate the two planned RCT PCB's.  All that's preventing me from continuing is needing to reorder PCB's from JLCPCB, receive the (right!) transformers, and... laziness.

  

 

 

Remote Control Timeswitch - Olde ETI project revamp...

And now for something completely different... besides the bitching & moaning that is normally my forte, as I'm sure I'll find plenty to gripe about here as well.

I came across & built this project from the long defunct magazine, Electronics Today International (ETI) way back in the early 90's - so yeah, I'm getting on a bit!

I loved the concept behind it from the get-go - superimpose control signals onto the mains supply, that could then be intercepted & acted upon by Remote Switches.  I also loved the fact that I'd be building from scratch, my own 'real'  computer - CPU, RAM, ROM, programmable input via the 6-button keypad, output in the form of the control signals that were being superimposed onto the mains and finally, a nice LCD display to program it with.  Yes indeed, a real computer!

The building of it was laid out over 3 issues (1,2,3), and the firmware was available free of charge for the price of a SAE direct from ETI themselves.  Construction itself was fairly straightforward, at least as far as getting it up and running.  The firmware was tapped labouriously into a Sinclair Spectrum 48K, which was then used to burn a 27C128 eprom via a home-made eprom programmer board stuck precariously on its backside.  In fact, this was my first experience with eproms and I actually bought new, specially for this project, the gear required for this, and which I still possess - 2 'black-light' tubes for developing light-sensitive PCB's, 1 UV tube for erasing the eproms, along with the necessary mains transformers to drive them.  These I got from two nice old guys somewhere in London, both of whom are unlikely to be still with us, rest their souls.

Anyway, build it I did, and work it did, at least to a fashion.  What immediately became apparent, was that the software was buggy - incredibly buggy as it happened!  For instance, the unit was incapable of operating for more than a day or so before resetting itself, which resulted in all of the time settings, as well as the time-switch programs, being wiped.  There was also the miriad of 'Power failure detect' messages that it randomly displayed, even when on battery power, that suggested that something was awry.

It had hardware problems as well, one of which I have only just discovered, much to my chagrin.  The first involved the pulse-width of the 50Hz pulses that were being derived from the mains.  This was solved by piggy-backing some additional circuitry onto the i.c. involved.  The other concerned the crystal oscillator.  For going on thirty years, I had always presumed this to be above suspicion.  Recently however, the unit stopped working entirely, so after a brief scope-check, I concluded that the crystal had 'finally' died, so ordered a new one.  I highlight, 'finally', 'cos at least 20 years previously, I had noticed on a crappy old Gould analogue oscilloscope that the frequency 'appeared off'.  I put that down to the crystal also about to expire way back then as well!  On swapping out the crystal with a new one, I was puzzled to find that it still would not power on.  Checking the frequency, I discovered that it was well over 10 Mhz - the LCD/keypad-i/f was only capable of operating up to 3 Mhz.  A quick google, soon revealed the problem - with the component values used, what you had was not a crystal oscillator, but a RC oscillator.  In fact, the RC values used completely negated whatever effect the crystal might have had, oscillating at the RC frequency whether or not the crystal was even in the circuit.  Using 'sane' values, I soon had an oscillator which produced a beautiful 1.8432 Mhz square-wave - probably for the first time ever!

But that was a present-day discovery.  Jumping back 25 years, the real problems all seemed software-related.  The firmware as it stood, simply didn't work, so I had the option of tossing everything into the bin, or debugging the software from scratch.  The latter was obviously the chosen route, and much to my surprise, it took only about a week or so.  I ended up with 8-10 pages of commented z80 code, removed all of the 'fatal' bugs, and discovered & removed 3-4 less obvious ones.  A problem I discovered several years on from this, was that, as it stood, the original code did not correctly 'form' the control-codes that were being sent out over the mains.  These codes determined which remote-switch was to be activated, the problem being that, say remote-switch number-4 was transmitted, remote-switch number-8 could end up being activated - so, not good!  As the entire remote-switch number generation is done via software, this proved a real pain to fix, as it meant that about a dozen eprom erase-burn cycles were necessary before I got it working properly.  What I wouldn't have given for an in-circuit eprom emulator way back then!

The one other real obstacle to fixing the firmware proved to be finding 'space'.  The original code takes up 4092 of the maximium readable (by the CPU) 4096 bytes of memory - an extra address line would have made things so much easier!  So, every time I needed to change something, I invariably had to first go and optimise the original code to gain a few more precious bytes.  This proved relatively easy initially, but it has gotten to the point where a very large percentage of the subroutines have been altered.  I was eventually reduced to merging individual subroutines in order to limit the number of 'push', 'pop' and 'ret' instructions that were needed.

Anyway, apart from the bug-fixes, and two little 'additions', the original firmware's functionality is still wholly intact.  The additions are keypad-related.  1) With the backup-battery connected, it is necessary to physically open the unit (or wait 20+ hours for a Li-ion battery to die!) in order to issue a reset - real tedious!  Now, by pressing both 'Sys' keys, the 'Down' key and the 'Entr' key simultaneously, while in 'Clock-mode', the system will be reset.  2) In Setup-mode, to facilitate calibration of the Remote Switches, the unit will normally send 13 'frames' to signal 'On', and 11 frames to signal 'Off'.  However in 'normal-mode', the number of frames sent is 16 for 'On' and 8 for 'Off'.  Now in Setup-mode, when the Xon/Off option is selected, by pressing the 'Down' key and the 'Entr' key simultaneously to initiate the sequence, the unit will instead use 16 & 8 frames when switching.  Number 1) in particular requires a 'knack' to pull off - all keys must be pressed simultaneously - but once achieved, it's easy from then on.

There are a couple of other vexing hardware related problems with this design.  One is that while the battery 'trickle-charge' circuitry does work, it will eventually result in the battery being destroyed, due to constant charging.  I've  been through several already.  The other problem almost defeats the entire raison-d'etre of the device.  Sometimes, after a power-cut, when power is restored, switching noise will cause the unit to reset itself, losing all stored programs.  I'll try to find solutions to these problems and post updates here eventually, hopefully it won't take another 25 years!  The original firmware, along with my final revision, is available here for download.

Finally, a word out to Mr Kevin Browne if he's still with us - Thank you for giving us this interesting project way back then - it's kept me interested anyway!

Edit:
A couple of months on, the unit is still on my work-bench, on test, its innards exposed.  I was intent on fixing the battery-overcharging problem with the aid of a small DC-DC converter - over-kill, I know -  and even ordered a few on eBay.  All for naught as it turned out.  Using a 9V Li-Ion battery with inbuilt protection is all that's needed, as its circuitry will electrically disconnect the battery when it is fully charged.  At least the ones I have from manufacturer Soshine do (good batteries, but take their advertised capacities with a pinch of salt!).

The resetting on power-recovery issue seems to occur only when the backup battery voltage is very low, around 6V, so should only be a problem if the electricity remains off for an extended period (15+ hours with the Li-Ion battery I'm using).

Finally, I found & fixed, hopefully the last 2 remaining bugs in the firmware.  Both were trivial display issues that didn't effect the unit's operation in any way.  One I was already aware of, the other, would only show itself if the maximum number of user-programs entered exceeded 255 - ordinarily, an impossibility, but zapped anyway.

Addendum.
While perusing my old collection of electronics magazines, I came across a follow-up article in ETI, a few months on from the RCT project, 'critiquing' the original work.  As I'd forgotten about it, I'll add it here for completeness, even though, imo, it was little more than a hatchet-job.

Several of the points raised by its author were frivolous, others without merit, while the rest are just plain wrong.  For instance, the radical notion of replacing the original regulated power supply circuitry (which works perfectly!) with a 7805 is ridiculous, if only from an aesthetic point of view. He also mentions swapping pull-up resistors, just a few K-Ohms in difference, as being necessary, and tying another pull-up resistor to ground, rather than to the positive rail - both incorrect!  In short, almost all of the component choices selected by Mr. Browne work fine, including those used in the various frequency-adjusting circuits.

The one thing he got right involved the 50Hz pulse-width that I've already mentioned above, although just using a different value resistor proved insufficient in my case, as the pulse amplitude gets attenuated below 'logic-level 1'.  I chose to include an additional Schmitt trigger, feeding it's output to a pot/capacitor pair, which allows the required pulse-width to then be set with ease & precision.

Edit:

I've spent the last few days removing 2 more original bugs that I first thought couldn't possibly have existed and that I must have introduced - but having checked the original firmware in action, apparently not!  Both concerned Program-entry.  The big one required a 30+ byte workaround, which I initially thought an impossible fix, given the imposed 4096 byte limitation - but apparently not there too!  Most of the space was found within a particular subroutine that was trying to do stuff that wasn't even necessary, the rest of the savings came from re-coding from scratch some other routines.   The functionality still remains identical to the original firmware, with zero features having been removed.  2.5 years ago, I was certain I had eradicated all of the original bugs - now I'm even surer!  The updated firmware is available from the original link above :) 

 I forgot to mention, my relying on the Soshine 9v battery's 'protection-circuitry' didn't go according to plan.  The protection circuitry appeared to work fine - stick one on a crappy old 9v charger - the type with no proper voltage/current regulation, and it would disconnect itself electrically when charged.  However, I've only just noticed that my once new & unused Li-ion battery has developed a 'bulge' from what appears to be from being over-charged!  Worse, it's ability to hold charge has also been decimated, falling from around 450mAh to a miserly 180mAh  - and all because of my laziness.  It still manages to power the control unit for 9-10 hours (down from 21-22hrs when new), so things could have been worse.  Maybe it's a result of all the power-cuts we experience around here - once the power reconnects, it will recommence charging.  Anyway, here's hoping this alleviates the problem...

 As a result, I've finally wired in a little circuit to limit the applied charging voltage to 8.4v, just 3 connections needed, with the 2 power-lines slotting in where R10, the current-limiting resistor used to be, and ground.  Better late than never!  Made up of a transistor, zener and a couple of resistors.  Works ok, although the little bc108 transistor gets a bit toasty when charging the battery from flat - hits around 75DegC. - even so, the supplied current never goes above 60mA.

One other little discovery I've just made concerns the remote switches.  Both of the two new builds have proven frustrating to get working properly, and though it should come as no surprise (to me), it's all been a result of those shitty bc108's from China.  This realisation came the other day while working with one unit, whose performance was abysmal.  Almost as a last resort, I swapped out the first 2 amplifiers, both of whose hFE's were in the 400 range, with 2 whose gains were just over 140 - yep, I was really grasping at straws!  Unsurprisingly, I ended up with a door-stop!  In one last final act of desperation, I swapped out the 1st input transistor again, but with a replacement that sported a gain of over 700.  The result was profound.  My once-barely-functioning switch is now by far the best of the three, reliably switching in remote parts of the house where none of the others will even operate.  Alas, it was my one-and-only 700+ transistor - despite checking well over 100 'Chinese' transistors after the 'discovery' - so at present I don't have the means to see if this 'fix' would work in the other switch as well.  I had & tried a bc108 that had a measured gain of 'just' 500+ ( the old one having been 400+) but it still won't operate from the 'remote' location.  

I'm really going to have to source some genuine bc108/9's somewhere.  While I realise that 'in-spec' bc108 (and BJT's in general) gains are all over the place, the alarming number of sub-100 gains that I've got through Aliexpress gives one pause for thought.  Given my recent post regarding the 2n3819 FET's that I ordered & which turned out to be NPN transistors, right now I feel like ordering from China is no longer an option.  It's one thing to be taking a chance and ordering out-of-spec components - like the bc108's I received seem to be - it's another thing entirely when they're labeling transistors as FETs.

Dragon Touch X10 Redux - (Rooting-pains)...

As a previous post here testifies, I bought a Dragon Touch X10 tablet almost 3 years ago.  I went from being thrilled with my purchase, to being appalled at how sub-standard the Android OS really is - at least Android's 4.4.x (Kitkat) to 5.1.0 (Lollipop) anyway!

Fast forward, a few months, I discovered that despite the rhetoric from 'official' sources, an 'un-rooted' Android sucks - there are just too many 'interesting' apps that require a rooted OS to work properly.  Enter Kingo rooting.

This was a god-send, or so I thought, when I originally went that route (sic).  With little effort, I ended up with a rooted X10, and with no apparent down-side - ie. everything worked as expected.  Fast-forward another year,  something fatally screwed up my tablet's OS, to the point that it would no longer even boot.  After freshly re-installing Android, rooting seemed a pre-requisite, so back to Kingo I went.  This time however, although I ended up with a rooted device, also included was a load of obtrusive crap that made the gains pale in comparison - the tablet powering on & off to load ads, when on charge, every minute or so, was the deal-breaker - one fresh Android install later, I was back with a unrooted X10.

But the thing that really sucked about Kingo was, part of the rooting process required that it be installed on Windows (Win7 in my case) first, and immediately on doing so, Windows would puke up a "...not genuine" error - and nothing could correct this problem.  Hell, I even reinstalled Windows/Kingo twice just to be sure that it was Kingo that was responsible - it was!  So yeah, KINGO SUCKS!!!

But even back then, there was another 'solution' available for rooting the X10, but it seemed way too complicated.  For one, the initial step recommended that BBQLinux be installed, as this included many Android-development tools.  Being the lesser of two (Kingo) evils, I decided to go this route, but was disgusted to find that after the installation, the BBQLinux 'rolling-release' encountered an error when I tried to update it.  Dejected, there things lay, until now...

Fast-forward to today, I decided to have another go rooting the X10.  My main fear all along was that 'flashing' it manually would 'brick' the tablet.  Two years on, I no longer cared too much if that occurred, particularly since despite almost no use, the screen had developed a fault - a single line of pixels, from top to bottom, are permanently switched on.

The only thread I've found that deals specifically with rooting the Dragon Touch X10 tablet is available here.  My first attempt resulted in failure, though thankfully, didn't result in a bricked device.  The error I made was in not following the instructions 'to the letter'.  I had seen that, viewed from Linux, the X10 partition type was a "mmcblkxx' type.  Based on this, I flashed - apparently, successfully! - the X10 with the recovery boot-loader 'TWRP'.  On rebooting the X10 however, nothing appeared to have changed - I booted to the same screen that the X10 had always booted to in recovery mode.  It was only as an afterthought, when I checked the X10's partition-type from the ADB console (check the link provided) that I was stunned to discover that my X10's partition type was not 'mmcblkxx' but 'nand'.

Reflashing the X10 with the alternative TWRP 'nand' image file, then rebooting, produced a very different result - ie. the new TWRP recovery bootloader!  All that was then necessary was to use it to flash the SuperSU (linked-to from site) file to the tablet.  And Presto - one Rooted-device!!!

The one other thing I discovered while doing this, and what prompted me to make this post, was that there is no need to install BBQLinux 'just' to root the X10.  Even my ancient Mint 17.3 (as well as Deepin 15.8) has the required ADB-tools in their repositories, needing just a few hundred KB's of downloads to achieve the same results.

Windows 7 - Renaming Device-names in Device Manager.

This post is mainly for my own future benefit, as I'm bound to forget the following procedure before long.  Hopefully though, someone else may stumble across this in the fullness of time and find it useful.

Needless to say, I've come across this issue before.  Admittedly, the problem is psychological in nature, as it really doesn't effect Window's operation, but I find it really frustrating when playing with Window device-drivers.

Insert a piece of hardware on your pc, install its driver and hopefully everything works.  Remove said-hardware, reboot pc, and Windows detects this and acts accordingly.  The problem arises when the same hardware is then reinserted.  Windows again detects it, but doesn't start with a 'clean-slate', instead, using the same device-name, appends a "#2" to it.  Do it again, and this number increases (#3 etc.), and continues upward with every removal/reinsertion - still just one device listing, with the same name, but an ever-increasing tail-end.  Given the number of problems I have had with Window's drivers, I find this maddening!!!

The problem isn't helped by the number of 'solutions' out there either - dozens & dozens of them, though admittedly, some address simpler renaming issues, whereas (many) others are just well-meaning individuals that haven't read/understood the problem and are providing even simpler, though useless, answers.  This problem has no simple fix, though there is more than one solution out there.  The first one I came across (years ago!) involved using Regedit - tedious, but it did work.  The latest & greatest fix, just googled, is much easier and takes a fraction of the time.  But enough of the preamble.

The first step is to create a system-variable - 'devmgr_show_nonpresent_devices'.  Working from the Start menu, left-click 'Computer'->'Properties', click 'Advanced System settings', then select the 'Advanced' tab on the pop-up window.  Now click 'Environment variables', then 'Add', and name the new variable 'devmgr_show_nonpresent_devices' as mentioned.  Give it a value of 1.

Now all there's left to do is (important) log out/back-in, and open Device Manager.  Go to the 'View' menu option and select 'Show hidden items'.  Of the Device causing offense, all items-names are now shown, including the all-important 'base-item' name.  Just delete ALL of these names, scan for hardware changes, and Voila!  Windows will reinstall the device's driver, using just the 'base-name' with no appended #x number.

Paypal Customer Support - Incompetence personified...

Four emails later to what Paypal laughingly calls Customer Support, and I'm admitting defeat.  Even though four(4) different people replied to my queries (List Of Shame: Ja, Surendren, Barani and Praveen) not one of these idiots could/would answer my question.  In addition to my naming-and-shaming of the individuals involved, I'm also including our communications below.

To summarise briefly, I contacted Paypal to find out how I would go about returning monies to Ebay Sellers that had previously Refunded (via Paypal) the same amounts(s) for orders that had failed to arrive - see previous post for details.  Prior to this, I had contacted Ebay's Customer Support and had been told;

xxxxx, the easier way for you to pay the item you received is find the transaction in your PayPal account, look for seller's email and click to "send money" to it.

 
Made sense.  So I contacted Paypal;

Hello. Although my question is about Refunds, Paypal's limited number of topic/sub-topic selections means I have to try and get my question answered this way. Simple problem, I have been Refunded money by a Chinese Ebay Seller because the order failed to arrive in a timely manner. Said order has since arrived and I am trying to return the refunded money to the Seller. The Paypal Refund information for this Seller lists his name (in Chinese characters (胥家良), plus his Ebay username (best-buy365) - THERE IS NO EMAIL ADDRESS LISTED!!! When I try to 'Send'money to the Seller, using 胥家良 or best-buy365, Paypal complains, saying it's an invalid name, and to enter a valid email address. How do I send money to a person when there is no email address listed in the Paypal Refund information? Or where do I find a users email address from their username?

Paypal Idiot No. 1's response;

Thank you for contacting PayPal Customer Support regarding your concern. I know this is important.

We’ve looked but are having trouble locating the specific transaction tied to your message. Can you help us out so we can provide a fast answer to your question? We look forward to helping you.

In most cases, any or all of the following information will help us identify the payment:

    Transaction date and amount
    Transaction ID number
    email address of the other party in the transaction
    eBay auction ID (if applicable)

We look forward to hear it from you.

It is my pleasure to assist you. Thank you for choosing PayPal.

Yours sincerely,
Ja
PayPal

My response included the ask-for Transaction ID number;

Hello, that was a fast response!

The transaction ID in question is 08F9511676205873U.  At least that's the main part of it - the Seller refunded in 2 parts for the same order ($26.96 and $1.46) - total $28.42.

And that's where it gets complicated!  Some Ebay Sellers provide separate refunds for each item ordered.  I don't know if you can access my Paypal Activity details, but it's presently a mess with Refund transactions from multiple Chinese Sellers.  I ordered en-masse via Ebay in November/December, and presently only about half of the stuff I ordered has arrived.  Multiple Chinese Sellers have already promptly Refunded my money when I put in a claim.  But when/if a order finally turns up, I'd would like to repay the Seller in question.

And this is proving to be a problem.  Why is there not a clickable button from a Refund transaction that will allow the Buyer to painlessly return payments?  There is not even the Seller's email address available - the very thing that Paypal is demanding in order to 'Send' money.  This makes little sense.

I hope you can provide an explanation/solution.

 Paypal Idiot No. 2's response, ignoring entirely everything I had written;

Thank you for contacting PayPal.

Although PayPal and eBay are closely linked, we are separate companies and we don't have access to eBay's systems.

You can contact eBay Customer Support by email, live chat, or phone. Please visit www.ebay.co.uk for further information.



Sincerely,
Surendren
PayPal Protection Services

Annoyed by this senseless reply, I shot off the following;

What a pointless response, that is nothing short of insulting!

You (Paypal) asked me for the Refund transaction number of the Seller I am having problems with, which I gave - again, its;

08F9511676205873U

I realise that Ebay and Paypal are separate companies - that has noting to do with my query. I am talking solely about Paypal's site-interaction here.

So let me be specific, to which I require a specific answer.

For Paypal user 胥家良,

(3 Chinese characters, copied from the Refund Transaction's 'Seller info' in case it's being 'filtered-out' in the Sent email and you don't see it),

the Seller who Refunded my money, how do I get a valid Paypal email address?  This I need in order to return to him the money he refunded.

How difficult can it be to provide this simple piece of information?

Paypal Idiot No. 3, also ignoring everything I had written, asks again for the same Transaction ID number, which I had already given twice;

Kindly provide the transaction id which is related to purchase of the item.

Yours sincerely,
Barani
PayPal

 I respond with a two-liner;

I have twice already (2 times!) supplied the transaction ID - so here it is agian for a third time;

Transaction ID: 08F9511676205873U

Paypal Idiot No. 4's response;

Thank you for contacting PayPal.

Although PayPal and eBay are closely linked, we are separate companies and we don't have access to eBay's systems.

You can contact eBay Customer Support by email, live chat, or phone. Please visit www.ebay.co.uk for further information.



You can contact eBay Customer Service by email or phone.

Here's how to contact eBay Customer Service:

    Go to http://www.ebay.com/ and log in to your account.
    Click Customer Support near the top of the page.
    Click the Contact eBay tab.
    Choose a topic that most closely relates to your issue.

eBay will provide an answer and, if applicable, further contact options by email or phone.

Sincerely,
Praveen

And Paypal's Customer Support is back to passing the buck to Ebay, despite the fact that in my very first post I explain that I had first contacted Ebay and they had told me to contact Paypal.

Is this seriously what passes as acceptable Customer Support in the eyes of Paypal - either ignoring the query entirely, or fobbing Paypal users off with irrelevant generic Cut & Paste answers?

It's a disgrace.  Shame on you Paypal.

Edit1:

Seen as Paypal's Customer Support was a no-hoper, I contacted Ebay's Customer Support instead, in a final cry for help.

As another order, placed on December 17, 2017 had arrived, I set about repaying what had been refunded to me via the 're-order-items-to-repay' route - only to discover that this Seller had 'blacklisted' me!  I can neither order items from his Ebay store or contact him by email.  So the only option available to me was to ask Ebay to contact the Seller to my behalf and aprise him of the situation in order that I could repay him;

Hello.  I could get no satisfaction from Paypal's Customer Support -http://omelettesbitsandbobs.blogspot.ie/2018/03/paypal-customer-support-incompetence.html.

I am hoping you can help on a related matter though.  A delayed order from another Ebay Seller (start-supership) that refunded me money has arrived, and I wish to return the money to him.  Unfortunately, this Seller has apparently 'blacklisted' me, as when I try to repay him by re-ordering the items from his shop, I am told that the Seller refuses to sell to Buyers that fail to "meet his requirements."  Plus, when I try to email him via Ebay, I am informed that the Seller is unable to answer my questions - so I have no means of contacting him!

Would you contact him on my behalf and tell him I wish to return the money that he refunded me?

Thanks.

Here is the response I got from Ebay;

xxxxx, I understand that you are a little confused and concerned on how you can repay the seller for the item you wanted. . I am a buyer myself and I have had experiences of having difficulties buying an item. Based on the information when I try to checked your account actually it indicate that the seller may have set up something in their listing that is blocking you from purchasing these items. I would just like to let you know that an eBay seller can set up in their listing and block certain buyers according to their requirements. We offer a number of ways for sellers to prevent and handle problems that may arise during transactions. What I can suggest is to find similar item that you can purchased since you cannot purchased the item again with the seller (start-supership).

I hope this information is helpful. Please let us know if you have other concern.

Thanks for choosing eBay , we value your business. You have a great day!

Yours truly,

Jay O.
eBay Customer service

 This dullard first implies that they understand my query, then "suggest" as a solution that I purchase similar items from a different Seller!  Items that I am already in possession of - WTF!!!!!  I'm getting the sense when dealing with Ebay/Paypal Customer Support, that I'm not dealing with real, thinking people, but some bewildering type of first generation AI that these clowns are trying to pass off as the real-deal.   How else can someone seem so clueless?!?!?

I'm appalled at what Ebay & Paypal offer by way of Customer Support.  It's truly a disgrace.