What's new
Pinball info

Register a free account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!

Wanted Williams System 7 CPU

JMP

Site Supporter
Joined
Aug 12, 2011
Messages
3,469
Location
Lancashire
Good working Williams System 7 CPU wanted For Laser Cue.

Have two already, but both seem to have developed similar fault not been able to get diagnosed/fixed. Ta.
 
I can fix those system 7 for you. What is the problem they develop?
But two boards with the exact same issue. Thats not very common. Maybe the problem is in another part of the game.
 
Thanks. Issue is they've been to two techs and I'm told they test fine on the bench.... I'm about to swap out the ROMS and PSU (despite already being rebuilt) as they are consistent things used between the two. But yes, could be something else in the machine doing it.... no idea what. All I know is when I installed my last NOS CPU, the game worked fine for months, so surely the boards, hence seeking another.

FYI, game hangs 1-2 secs after switching on. Only boots if coin door connector disconnected (or door left open) and CPU reset switch pressed.

If I can't find another I may send both to you, thanks. Maybe I will be third time lucky !
 
Well, I have a system 7 board here tested and working. Maybe I can send it to you so you can test a third board. But, lets try to discard another issues before.
When you turn the game on, it goes to attract mode? or audit mode?
Did you tried another ram in those boards? another 5101? Weird problems related with the door, testing, is always the ram. And those 5101 are very sensitive.
 
Well, I have a system 7 board here tested and working. Maybe I can send it to you so you can test a third board. But, lets try to discard another issues before.
When you turn the game on, it goes to attract mode? or audit mode?
Did you tried another ram in those boards? another 5101? Weird problems related with the door, testing, is always the ram. And those 5101 are very sensitive.
Thanks. One board has a 5101 chip to use with batteries and the other an NVram (and I have tried swapping both over). The game boots to attract but hangs after 1-2 secs with both of these fitted. I then have to open coin door and reset cpu, game boots/starts and game can be played. With the other cpu, this wasn't possible (with 5101 installed) but similar 'hang' at switch on, nothing in displays and 0 (cpu lock on) showing on that cpu.

Any help to you? Thanks

Appreciate offer of your board to try, cheers
 
Can you play the game with the door open? What happens when you close the door? Tha game stop? freeze? Could be a problem with the door wiring or an issue related to the door switches.
 
No.. just needs to be open or connector removed when resetting cpu to get it to boot. Open and closing once booted does nothing.

Suspected this some time ago with latest boards installed that worked well for months so had the connector removed from board in case. Still got fault...

Small development today, re-seating nvram gets it to boot normally once, second switch on reverts to hang. Almost every re-seat gets it to boot once. Wierd....

Going to replace roms tomorrow to rule out. Already tried another psu and disconnected sound board, no difference. With it working briefly with nvram re-seat I'm wondering about the socket but going to try rom replacement first.

Cheers
 
Most of the time sockets in this boards must be changed. But as you told me this boards have seen by a technician I supused the sockets are new.
 
Most of the time sockets in this boards must be changed. But as you told me this boards have seen by a technician I supused the sockets are new.
Was replaced for the NVram install but suppose it could be dodgy... going to try the board in another System 7 machine if ROM replacement doesn't work. Keep chipping away but still open to another board to buy/try if available.
 
Bump.

Testing my existing ones in another machine, but still open to buy a good working System 7 CPU. Ta.
 
I can fix those system 7 for you. What is the problem they develop?
But two boards with the exact same issue. Thats not very common. Maybe the problem is in another part of the game.
What's the ballpark cost getting a System 7 CPU/driver board sorted?
I have the ones from my cg laying around I feel I should maybe do something with. (the machine currently lives in the office so can't really use that to test it out if I was to try and repair myself 😁j)
 
Suppose depends on what needs doing. I've spent around £150 so far and they're still not working properly,
 
Last edited:
I recall Bob Thomson telling me that a lot of L7 boards have a strange finish with poor adhesion of the traces, so it's even easier to damage them during repair. Tallying with this was one in the spares stash at work, the Cpu board from a Black Knight*. The Cmos Ram location had so many traces lifted that a 'wire wrap' socket, standing an inch off the board, had been fitted in order to connect with prototyping wire.

* how could I tell, with the machine long gone? The label bore a 5-digit number ending '00', maybe 32100. The 00 tied to Black Knight's number of 500. Though the stripped down playfield still hanging around was a clue..
 
Last edited:
  • Like
Reactions: JMP
What's the ballpark cost getting a System 7 CPU/driver board sorted?
I have the ones from my cg laying around I feel I should maybe do something with. (the machine currently lives in the office so can't really use that to test it out if I was to try and repair myself 😁j)
Usually, around 60.
 
Bump.

Testing my existing ones in another machine, but still open to buy a good working System 7 CPU. Ta.
@Chilpin FYI both boards don't work in the other System 7 machine and are non-booting on another test bench (!) so hopefully going back to original repair tech.

Still looking for a good working System 7 CPU as backup. @Chilpin you up for selling that one you have?
 
Last edited:
@Chilpin FYI both boards don't work in the other System 7 machine and are non-booting on another test bench (!) so hopefully going back to original repair tech.

Still looking for a good working System 7 CPU as backup. @Chilpin you up for selling that one you have?

As I repair machines I like to have at least 1 working CPU for every game generation. And this is my last system 7 board and they dont go for sale very often. I prefer if you send me one of your boards for repair or test.
 
I prefer if you send me one of your boards for repair or test.

Offer still there? If so, are you able to machine test after repair?

Got one set back and now working but the spare has garbled displays (but does boot). Thanks.
 
I dont have a game to test it now.

OK. issue is previous work has resulted in now booting under bench test but displays garbled when installed in a machine. I know someone who can bench test including the displays but it'll be on a forever wait list.

Ta anyway.
 
Last edited:
Back
Top Bottom