Data East CPU board repair

[ronnie63]

I picked this up from a recent sale thread on here for a great price! Needed some work! Missing cpu, ram, 2 x pia and a 7408, luckily I had these parts to hand, So it had a badly butchered pia as circled in the picture! I had no option but to cut this out, there is lots of through hole pad and track damage! so all these tracks and pads had to be remade. Also a transistor in the lamp matrix had suffed track and through hole damage also circled.

 

[ronnie63]

So this is after removing the pia and cleaned up a bit revealing the damage! Much work to do



And then the fiddly job of remaking the damaged traces!


More to follow!

 

[ronnie63]

So all the traces repaired and checked, solder resist applied and new socket fitted



The 7408 som minor track damage repaired socket and new chip fitted



The tip142 area cleaned up new through hole rivets fitted and damaged tracks re made removing the horrible jumper wire! Waiting on some new transistors to complete



There might be some more areas to go over and tidy up but the worst is done

 

[ronnie63]

So after all the above missing chips replaced and leone’s test Rom fitted I’m happy to report the board now boots and all pia outputs are cycling as expected I have still to check all the inputs and outputs once I get the new tip142 but so far looking good, once all that’s done I will properly test it in a machine to make sure it’s fully working as should.

I hope this post is helpful to others and shows with a bit of time butchered boards can be saved.

Cheers Ronnie

 

[pinballmania]

Good work. How many hours so far?

 

[Paul]

So after all the above missing chips replaced and leone’s test Rom fitted I’m happy to report the board now boots and all pia outputs are cycling as expected I have still to check all the inputs and outputs once I get the new tip142 but so far looking good, once all that’s done I will properly test it in a machine to make sure it’s fully working as should.

I hope this post is helpful to others and shows with a bit of time butchered boards can be saved.

Cheers Ronnie

I picked up some PCB VIA (Through hole) rivets the other day.... looking forward to seeing if i can replace some of those through hole issues (i know the standard practice is to stick a few strands of wire through the hole if the VIA's have been trashed, however that doesnt sit well with me, especially since some of the issues are around higher voltages/currents).

 

[ronnie63]

Good work. How many hours so far?

I would say off and on about 2 hours

 

[ronnie63]

I picked up some PCB VIA (Through hole) rivets the other day.... looking forward to seeing if i can replace some of those through hole issues (i know the standard practice is to stick a few strands of wire through the hole if the VIA's have been trashed, however that doesnt sit well with me, especially since some of the issues are around higher voltages/currents).

Yes they are handy to have as they stop the transistors wobbling about! for the pia's I used kynar wire through the hole and made it long enough to wrap around the pin of the socket solder side which creates a pad to secure the pin to the pcb, this is fiddly but works well, I think using rivets for so many pins would be a nightmare!

I got a whole set of these rivets in various sizes from a place in Holland they were expensive for what they are.

 

[Epotech]

Just about to start on my de sound board, died after Swavesey. Hopefully just a re cap and not major surgery like this!

 

[Paul]

I got a whole set of these rivets in various sizes from a place in Holland they were expensive for what they are.

I got a set on Amazon i think (Or Ebay) It was £9 for 1000 of differing sizes. Not tried them yet, but worked on the principal that they cant be that bad - are only a piece of metal