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Andrew96_

Mecca Supporters 2019
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Everything posted by Andrew96_

  1. Andrew96_

    SRU Processor Required

    They are pulls and have a extra identification number on them which I have been unable to find out what equipment they came from so far
  2. Andrew96_

    Diamond geezer help

    OK those files don't appear to be available from Barcrest. you will struggle with that rather like putting please and thankyous in your very 1st post! not even a proper introduction good luck in your quest
  3. Andrew96_

    Crediting up Electro's

    Mpu4, Dip 2.8
  4. Andrew96_

    Crediting up Electro's

    isn't it something to do with the law at the time like for Isle of white or jersey? (cannot remember which area now) single coin entry was usually switchable on machines to comply with the law, usually done on one of the dip switches
  5. Andrew96_

    Dutch MFME machines

    most likely anything he can get for free without giving any resources to the forum, does that about sum it up?
  6. Andrew96_

    Funny advert

    here is another good one! see this today in a junk shop type shop! so asked how much!!! (as you do) £2000 as is was the answer! well needless to say I did not buy it! that's the price it would fetch restored! not the price as it stands with all that nasty white mould on the woodwork under the glass!! chrome metalwork on the playfield was rusty! I never bothered to ask if it actually worked! if it did the mpu would be full of battery rot too! so decided to leave it lol!
  7. Andrew96_

    sys80 psu fault

    have you checked the 5v fuse?
  8. Andrew96_

    Epoch engineers!

    I have looked at a couple where the tracks rot away under the processor, that's why I said not to bother as the rot on the processor pins looked very similar to the ones I had, next move I think is to remove the processor and see what it is like under it, the green rot between the pins needs to be throughly removed, took me well over a hour on each side of the processor to clean up the rot good enough in the pictures above, so that alone was 6 hours work
  9. Andrew96_

    winsprint jpm sys80

    most likely the 50v fuse has gone on the psu for the solenoids especially as the meters are working fine
  10. Andrew96_

    mpu 5

    Battery flat, needs replacing then your get the error 'ram corrupt' and this will then nead clearing of the ram or it still will not work. been covered to death on here, see this thread https://www.fruitemu.co.uk/ib/index.php?/topic/20915-hola-amigos-barcrest-noob-here-need-some-help/&tab=comments#comment-321441
  11. Door switches will not cause that problem!
  12. Andrew96_

    Maygay m1a repair thread and tips

    well this is a first! first time I have had one of these Toshiba 8279 chips fail causing a M1 board not to boot! It stopped the data lines communicating properly cross the whole of the board!
  13. Andrew96_

    1984 MPU3 Naughty but Nice

    and don't forget ALL the gallery content since about 2014 went too! I guess the developers just decided forums don't need that anymore either along with the search facility! so we are now stuck with a old empty wooden pusher case which by now has either been eaten away by woodworm, or scrapped! but we MUST have to see it EVERY DAY, technology IS actually going backwards now!
  14. Andrew96_

    Epoch engineers!

    clean that rot out between the pins of the cpu! like this
  15. Andrew96_

    Epoch engineers!

    C38, 100nf 50v C3 and C4, 33pf 50v
  16. Andrew96_

    Epoch engineers!

    It is BC846B as I have just checked
  17. Andrew96_

    Epoch engineers!

    Q1 appears to be BC848B I believe, difficult to tell from the diagrams as they are bad!
  18. Andrew96_

    MPU4 Motherboard Repair WELL ATTEMPT

    Yes I have found this, removing the battery does not stop the rot, it’s like a vinegar wash, once you do it the vinegar acid gets in and under everything just slowly corroding especially copper away! Battery alkaline is much slower once battery is off but it does happen! Well I have seen it for sure!
  19. Andrew96_

    MPU4 Motherboard Repair WELL ATTEMPT

    no they are 50v and I do have some 48v bulbs, BUT I cannot find my 50v psu so using one of the green directive ones which are 24v not 50v so the bulbs are 24v (it is about 4 or 5 years since I used the 50v psu and don't know where I put it!) I like to make sure ALL the triac outputs are connected and working, I have hears stories in the past where boards will not pay out in a 3 reel machine but put it in a clubber and it pays out fine! this is because each use different triac channels so it is pot luck it which triac channels are dead and which machines they work in! but by checking them all it proves to me they are all working and fine! it is a bit 'heath Robinson' lash up the holders but least it does the job and knocked it up with bits I had, a old bit of wood and did not take much time to make!
  20. Andrew96_

    MPU4 Motherboard Repair WELL ATTEMPT

    well I am quite sure that is exactly what happens with the laminated PCB boards the rot gets in it somehow, but for some reason others have a hard time believing it actually happens! I did find it was more prevalent when the weather was colder. guess it all depends on how the boards were stored in the past and how the battery has affected said boards! after all the rot gets under the solder resist in the first place so why would it not penetrate the board as well! we all know rot affects the solder side of the board as well so attacked from both sides! So I have always planned to build a rig for mpu4 but firstly never got around to it and secondly when I stopped doing repairs interest in building rigs etc disappeared! so today I just knocked up on a bit of wood lamps so I can see what all 8 triacs are doing and when they are firing! don't laugh but this is the result! all just rigged up on the bench so I can work on the board and be able to power it up too!
  21. Andrew96_

    Epoch engineers!

    chuck it, thats too bad my repair thread is here https://www.fruitemu.co.uk/ib/index.php?/topic/20733-maygay-epoch-mpu-repair/
  22. Andrew96_

    MPU4 Motherboard Repair WELL ATTEMPT

    on a better note, I bought some if these for the volume control replacement some time ago, but now I am doing MPU4 boards thought I would see if these fit on a couple of boards I have that needed them, so far so good!!
  23. Andrew96_

    MPU4 Motherboard Repair WELL ATTEMPT

    No Bob I don't work like that, I like to find out what is causing it and if possible come up with a fix! so I have Bobs board (no3) which fires triacs before it boots, and one of my own stock ones which is perfect, so I started by removing IC8 on both good and bad boards, this eliminates any spurious voltages coming out from the chip before bootup. powered each in turn up and measured the voltages on the base of the triac driver transistors, sure enough on bobs board there was around 1v on the base, on a good board there was nothing!! So IT IS voltage appearing on the base of the transistor turning it on firing the triac before the base is clamped at 0v when IC8 6821 PIA port is initialized! just as I suspected!! squirting the area with a bit of IPA and the voltage is then gone!! great!!! but leave it a while so it all drys back out and voltage and triac firing is back!!! Now I have had this exact same thing before in the battery rot catchment area on a different board and been told this cannot happen! the PCB cannot change properties due to battery rot damage impregnating the board but how can it be anything else but rot getting into the laminate of the board? it does not happen in any other areas, just where the battery rot area is! to me it seems these are all in very low voltage areas which take little current, transistors turn on at 0.7v with very little current on MPU4, and in PC92 it is the same in the battery rot area. spraying IPA cures it in both cases to cure for a while, but a few hours later when it dries out the faults are back! it seems the board has leakage voltage when dry but this dissipates when IPA is sprayed. just waiting now for the board to completely dry out of IPA residue from the laminate layers then I believe I have a work a round for it to cure it once and for all of the problem. but for the second time am I trying to invent a cure for a problem that does NOT exist I wonder........ I guess I am being fooled by something no one else has seen yet again!! but it is weird how this is not the first time I have seen this and the circumstances are the same, just different manufacturers boards. has to be me I guess!! I better wait for the hate posts telling me again this cannot be the case!
  24. Andrew96_

    MPU4 Motherboard Repair WELL ATTEMPT

    So after fitting the 33 ohm in the other board and testing tonight on the bench with the test software, board no 1 and 2 both appear fine, triacs and switch strobes all working good now meter outputs all good, lamp matrix etc all seem fine, so next move is to test in a machine, so that is 2 good boards now, and a fix for board no 3 triac firing is well on its way now!
  25. Andrew96_

    MPU4 Motherboard Repair WELL ATTEMPT

    well that's fine but the switch inputs go to one port of IC8 6821 PIA chip set as inputs, and the triac drives come out the second port of IC8 6821 PIA chip set as outputs, but they are only set once the reset is done and code runs to set them up, the triacs firing happens before the reset happens, once the reset happens the triac firing stops, that's why you get them firing at board powerup before the reset! that is the problem, this is not my first board I have had with this problem, back in 2012 when I did them I had this exact same thing, but how can it be it seems to be just me that has experienced this! (and it also seems now midibob has too), perhaps others just use them for spares! just wondered what others that fix boards do when they see this problem
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