WPC 95 1 and a half beeps error.

[aurum]

That'll do it. Thanks.


Think I'll leave the unsoldering of the PLCC until next week, done too much already this week.


Mike.

[aurum]

The PLCC100 (not 84 as I earlier thought) socket finally arrived and after much solder sucking the board is ready to accept the new one.


New socket soldered in and success - all working again.


A word of warning for anyone attempting this, the asic can go in the wrong way around - luckily I checked before powering up - the writing should be the right way up when in the machine.


I'm now considering using a 18650 battery with a battery conditioning and charging circuit as the battery backup. Anyone any thought on this? Fire risk?


Mike.
Edit, how do I remove the extra attachments? Every time I try I end up with more!!

[aurum]

I may have spoken too soon . It worked fine for about 3 hours and I've now got a dead CPU board. I now have the blanking LED(201) permanently on and the Diagnostic LED(203) permanently off. Think I'll wait until tomorrow to power it up on the bench and try and diagnose the problem. Anyone any pointers? Also, anyone know what current is taken from the 5V supply by the CPU board alone?


Mike.
BTW, the PLCC is 84 pins - don't know why I thought it was 100 earlier.

[aurum]

Just powered it up on the bench and started to trace the blanking signal. Got half way through tracing it and it had the wrong polarity because the blanking LED had gone out and the diagnostic LED started flashing. Put it back in machine, worked for two minutes then back to dead.Back on bench, 30 seconds later working again!!! It's now back in the machine and appears to be working fine but I suspect there is a faulty connection somewhere. Time will tell.


Mike.

[Strangeways]

Sounds to me like there may be more corrosion at play here. If there was no history of corrosion, I'd say that the issue could be the sockets - CPU, ROM and 6464, or the ASIC is loose. With the game on the bench, you need +5V but I always have +12V as I simply use an old PC AT power supply. With the CPU PCB on the test bench, see if you can get it to fail - push the ASIC in and the socketed chips until it locks up. If it does not, then it will be something on the driver board, or the ribbon cables.
Have you got another machine to swap out ribbon cables ?

[aurum]

The error appears both on the bench and in the machine. The error first disappeared when I tried tracing the RST line as the 6809 was being held in reset. Whilst tracing this signal the board sprung into life. It then worked for a short time in the machine but at the next power cycle the error returned. As it was whilst checking around the 7414 that it came to life, I swapped that for a new one. I've now changed also the asic and the 6809 but the error persists. Once the board springs into life it continues working until the next power cycle. Tomorrow I'll try resoldering the whole board in case there's a hairline crack somewhere.

Mike.
Edit, why is this being posted with a tiny font size? Just had to up it to 12 to see it.

[Retropin]

Intermittent faults are painful but im assuming that when you tested the 7414 you were testing voltage or signal on the pins. If its in a socket, id be replacing that straight away. It only takes a nano second for the logic signal to drop out. Corrosion may have eaten into a few traces also and so a rub back and solder flow may be the way to go

[aurum]

I've finally got around to looking at this again and simply went over all the replaced components and resoldered all the connections. So far, fingers crossed, it is all good again. I deliberately held the iron on longer than normal to allow the solder to melt all the way through the hole and that seems to have done the trick.


Mike.
Edit, late Friday here - time for a well earned beer.

[DSB]

Good to hear! 

[Strangeways]

Hopefully it is all good from now on !

[aurum]

All's been good for 3 days and many power cycles so hopefully the problem is solved. Just got to fix the up/down table for Frankie now.


Mike.