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Elektra stuck at 2 flashes

HomerRamone

HomerRamone

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HomerRamone
This is sort of a continuation of my previous thread - which started life as Elektra blowing the fuse. But thats kinda gone off topic too so I thought I would start a different thread in the hope someone can point me in the right direction.

So having gotten Elektra to power up, I was getting 2 flashes on the MPU when in the machine (mostly - suspect the power board needs an overhaul - I have the bits for this just not done it yet :) )
Took the board out and used a PC PSU to supply 12v to TP 2 and 5v to TP5 (and GND of course)
This gave me 1 flash. OK progress - sort of even if in the wrong direction.
1 flash the RAM. So I changed U7. Swish now I have 2 flashes again. Consistently.
2 flashes is U8 - the CMOS RAM - I had one of those. Excellent. Replace the CMOS. And.... still got 2 flashes.

Looking at the schematics I concluded the next port of call was U17, U18 or U19 - all of which were linked to the CMOS chip. These are logic gates and inverters. I can test those (I think).
So I set about it last Sunday armed with my multi-meter.
After much probing I found one of the outputs of U18 (4049 - which is an inverter) didn't look right. 0v at pin 7 and 0v at pin 6. Decided to whip it out. Or at least asked my mate to do it who is usually better at this than I am.
Alas his eyesight has gotten worse than mine over the years, and hes waaaay out of practice.
The legs of the chip were bent over (presumably in the factory by a machine?) and this made it troublesome to get the (possibly) offending chip out.
As a result when the new socket was soldered in and a replacement IC insert.. Instead of 2 flashes I got a constant on LED :(

I set about it again with a meter last night and checked the tracks in the area. Discovered that 3 tracks have been damaged when removing the old IC. Figuring its busted for sure now I probably cant make it any worse. So I broke out soldering iron and set about working around this !

Having done this I'm now back to 2 flashes - so progress after a fashion.

So I kinda made progress but only to get back to where I was already. U17 looked ok when I was probing with the meter and I think U19 was too - though maybe I will check this again.
Anyone else able to suggest what might be causing this. (Other than the obvious "you killed the CMOS with static when you fitted it.. might order another chip anyway - cant hurt)
 
Definitely two flashes and not counting the first false flash?
 
If you short pin 39 and 40 on U9 does it boot?
 
Not tried that - will try it these evening. IIRC pressing the reset button when its done the 2th flash doesnt make it flash 2x again.

Thanks
 
If the reset circuit is toast the button won't do anything.
 
Let me know when you test it tonight.
 
Just a thought - you dont need the battery installed to get past the 2th flash do you ?
 
Deffo shorting the correct pins? That will reset the cpu and start the flashes again.
 
As was saying in the other thread. Ram issue. Change 5101 ram with ram from known good supplier (like me!) and change socket. Be VERY careful not to wreck the board/pads/traces if removing the socket yourself
 
Changed the IC but not the socket - the socket appears to be fine.
I mean I can try another CMOS chip in case I killed it when I installed it, but I installed one in Gorgar (which was sourced from the same place - pinball mania) without issue so i''m not sure its going to help. (Wont help to have a spare either I guess)
 
HomerRamone said:
Changed the IC but not the socket - the socket appears to be fine.
I mean I can try another CMOS chip in case I killed it when I installed it, but I installed one in Gorgar (which was sourced from the same place - pinball mania) without issue so i''m not sure its going to help. (Wont help to have a spare either I guess)
Click to expand...

if the ram came from Andy/pinballmania then it’s fine. Concentrate on the socket and remove u10 to until you get 3 flashes to
 
I have my toys now perched firmly on the edge of the pram at this point.
Took the CMOS socket out this evening and popped a new one in (having ordered another CMOS just.. just in case). checked all the connections from the socket to the respective connections on the board.

Now Im getting mostly 1 flash (an sometimes 2). Evil forces are at work here methinks. (Wanders off to the internets to ponder alltek boards a little more)
 
Gah. PinballMania also has no 6810 in stock at this point.
Evil forces are at work I say !

And to add salt to the wound the CMOS chips arrived today. :eek:
 
****ing in the wind springs to mind your just wasting your time and money guessing at stuff and if you don’t have good soldiering skills then do more damage than good just send the board for repair or buy a new one
 
Thanks - that's helpful for sure. (Though i'm not sure how you know this is a result of my soldering)
 
Thanks - that's helpful for sure. (Though i'm not sure how you know this is a result of my soldering) [/QUOTE said:
Maybe Chris’s basing it on the fact that before you removed the socket you constantly got 2 flashes, now you’re getting 1 or sometimes 2. So something’s amiss
Click to expand...
 
Maybe - It is however possible that there's something wrong with the RAM IC as indicated by a single flash. The socket for that isnt exactly in great shape either.
That isnt to say down to my soldering - but according to the multi-meter all is well with the connections on the socket I actually replaced.
In any case suggesting im wasting my time an money is just not helpful here I feel.
 
HomerRamone said:
Maybe - It is however possible that there's something wrong with the RAM IC as indicated by a single flash. The socket for that isnt exactly in great shape either.
That isnt to say down to my soldering - but according to the multi-meter all is well with the connections on the socket I actually replaced.
In any case suggesting im wasting my time an money is just not helpful here I feel.
Click to expand...

If you are happy having a crack at sorting it out then go for it. But talking from experience there sometimes comes a point for your own sanity when buying an Alltek, and opening a cold beer is the best option :thumbs:
 
You might well be right. But then if I get an Alltek board then it don't matter what happens to the original MPU. It doesnt work now so I've nothing to lose there. (Although I might discover a bunch of other busted stuff once I plug a new MPU in - if I give up trying to fix things then it could be said spending £150 on an MPU is more of a waste of money than £10-20 on a few chips and transistors and such

Just feels like admitting defeat getting the Alltek board - especially since I got the machine to try and make it work again. (Which I managed to do with a Centaur, Barracora and Mr and Ms Pacman a number of years back).
There's nothing to stop me doing both I guess - I can get the replacement MPU and still try getting the existing one working :)

I've had a bunch of useful information from folks here and its greatly appreciated I just thought that the above comment was just not helpful in any way.

(Might I add at this point, I did manage to recover from stuck on LED to 2 flashes again. And as I mentioned above the stuck on LED wasn't actually caused by my mediocre soldering ! Not suggesting my wire fixes were exactly neat and nor am I suggesting my soldering is great - but they solver the problem so...)

Oh and of course I have an Addams and Whodunnit to play whilst I drink a refreshing cold ale - ale will deffo not help my repair skills :D
 
I found the alltek useful for diagnosing, if it works with the altek you know the problem is on the mpg boardsomewhere etc

it yeah it’s also £150 which doesn’t need spent until you wreck the existing one 🤣

i nearley sold my altek a while back as I got rid of a load of the machines it supports, down to two now so will hold on to it a while yet...

good luck with the tinkering/repairing
 
I wasn’t been unhelpful but you are just guessing on what’s wrong with it and just throwing time and money at it with no idea you are going to mend it your soldering skills must to a good level and have the correct equipment to to a good job if you don’t you just cause more damage you did have 3 flashes now 2 since you have done work on it so it’s now worse
I have done the same myself years and I am very capable of diagnosing problems and repairing boards but it’s much more efficient just to send it to someone who knows what they are doing rather then waste hours on it when they probably know what’s wrong with it and can repair in mins
 
I am indeed guessing whats wrong - however I was looking for advice regarding what the problem could be not regarding money or time. (If money and time was important to me here surely wouldn't have bought a broken pin to try and fix it ?)

You are correct saying that I don't know whats wrong with it. I know what the flashes indicate but having changed those ICs and the issue persists I was therefore looking for advice on other things to try.

Also, as I mentioned previously - It wasn't my handiwork that took me from 2 flashes to 1. But it was my handiwork that got me back to 2. (Not boasting just pointing out im doing something passable).

However, It was my changing the socket that subsequently sent me back to 1, but since I also removed the chip that's linked to 1 flash then possible just perhaps that either I've done something to that chip (or its socket for that matter)

The board wasn't working to start with and having someone else repair it for me will teach my nothing. (And cost me way more than the £15 or so I have spend on some ICs and sockets).
It is quite possible that once repaired the board may well fail again in a few months is it not ? So then I would have learned nothing and STILL have a defective board ?
 
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