21 Feb 2018

Pang - Capcom_Mitchell 1989 (repair log)



Game had committed suicide. This hardware should display a plain light blue screen when suicided but this one gave nothing, no sync signal: sure there was more work than just burning the decrypted ROMs and adding few wires.

Anyway board was covered by a greasy liquid I reckoned was CRC or WD40. No idea why...
So first I removed the socketed chips and it went in the sink for a bath:


Once dried I followed the desuicide procedure found on the "Dead Battery Society" website (http://www.arcadecollecting.com/dead/), and then fired the board: nothing, no sync just as before.
I probed the main CPU and found no activity at all, not even a clock. So I moved to the crystal and it was pulsing fine, however on the part side I found a ferrite with a broken leg. This ferrite was connected to the output of the crystal so that was sure a big issue:


I replaced it:


And the game booted to a corrupted title screen:


Well this time I was responsible for it, I read PW on the ROMs (for Pomping World = Japanese version of Pang) so I used the Japanses decrypted ROMs. What I missed was some ROMs had PWE written on them: this was the World version of the game hence Pang. I burnt new ROMs with the World version decrypted ROMs and title screen was now correct:


However text layer was missing...


By probing few chips I found no activity on one of the outputs of the LS157 @ 7E. Inputs were not pulsing either: one was connected directlty to ground and the other lead me to another IC. Again no activity on both concerned output and input. I followed the signal from one IC to another and finally while tracking it down I found a trace has been severed and made connection with a pad nearby:


I removed the unwanted connection and the game played 100% correctly:



Game fixed.


2 comments:

  1. nice job as always :)
    i resurrected a Super Pang using arcadehackers arduino patcher. worked perfectly. and yes it runs on the battery, but the resurrection is cleaner than the wiring and new eproms :)

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    Replies
    1. Thanks. I've got the Arduino too but having more than 50 games originally equipped with a battery it was too much work replacing all of them every 5 years to play it safe. But surely it's nice to have the ability to put a battery back in the future.

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