I haven’t wrote one of these in a while and have a back log of repair logs to add at some time but for now let’s start with my most recent project to get back into things and maybe try to work backwards a little before I forget everything…
SEGA System 16B E-Swat ROM Board Repair:
I had been watching an auction for an over priced E-Swat ROM board for a while:
It was the discarded left overs from yet another Dark Soft Multi where only the System 16B Motherboard was required. It was listed as working perfectly but you can clearly see a capacitor is half ripped off and the CPU that held the encryption key for the PROG data was missing.
I contacted the seller, but he was adamant it works perfectly fine and found out he had just thrown away the old CPU when he replaced it with a regular 68000 for the multi to work.
So I left it some more until eventually after many months it got discounted down to £25 and I decided that was low enough of an amount for me to take it on.
As I had already noticed one of the capacitors was just barely hanging onto the board:
So I removed it and cleaned up the via’s of the old legs:
Then replaced the 470µF 16v capacitor with a spare (and slightly taller) 470µF 25v capacitor I had to hand:
I also noticed that the custom SEGA 315-5248 IC on the reverse of the PCB has flux remnants:
It looks like a few IC legs in one corner were re-soldered back down at some point in the past.
I double checked continuity (which was good) and just cleaned up the flux.
I then removed the PROG EPROM at IC positions IC1 and IC2 and dumped their data using my Universal Programmer.
Once dumped I compared their CRC and discovered they are identical to the E-Swat SET 2 JAPAN (eswatj) ROM in mame so I just needed to take the decrypted PROG ROM files from (eswatjd) and program them to two 27C2001 EPROM.
Unfortunately I was having problems with the ST M27C2001 I had spare having stuck bits so I ended up erasing the original NEC D27C2001 and re-programming them instead and placed them back in their appropriate IC sockets:
Then using some IPA I cleaned off the marker pen:
Then I cleanly removed the “O.K” sticker label and finally replaced my Shinobi ROM Board with this E-Swat ROM board:
It lives again: