1 Feb 2018

Capcom 85H001 (sound module) reproduction - part 1

This module has been a real nightmare for me for years as its failure rate is quite high...
Unfortunately to save a game you have to sacrifice an other one as there's only one module per game.

I know of 3 different flavours (there might be more) which are interchangeable between games (I tested it personally) :
- Ceramic module without any marking: seen on Makaimura first run for instance
- Plastic module ref. 85H001 5I
- Plastic module ref. 85H001 5H





Affected games are (from the top of my head):
- Ghosts'n Goblins/Makaimura
- Avengers
- Legendary Wings/Aresu no tsubasa
- Section Z
- Trojan/Tatakai no banka
- Gun Smoke
- Black Tiger/Black Dragon

I already designed a replacement module which I tested on Trojan and GnG based on my observations and schematics of earlier games but I couldn't guarantee it was a 100% perfect replacement.
So recently I took the decision of decapping the ceramic module of my Makaimura first run (as it seemed a lot easier to me to dissolve ceramic rather than plastic).

Before soaking it in a basic (soda) solution I removed with a sharp knife the ceramic layer on top on each IC to be able to read references in case the soda washes them out (which it did!):




The module after a 24h soda bath (I added references):



I then drew the schematics and assembled a prototype with through hole parts:



And tested it successfully on real hardware!



Next step is to route a board the exact same size the original one with SMD parts.
Stay tuned!

 [EDIT]
The prototype tested on Trojan:





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