Sega Mega CD 2 failed BIOS swap - damage repair advice?

Hey guys,

So a while ago I picked up a non-working Mega CD 2 off eBay. Had a no power issue, so figured it'd be the fuse. Checked the fuse, all was OK. On closer inspection, it looks like someone had tried to desolder the BIOS chip (most likely to replace it with a region free one, which is actually what I would have done too once I got it working).

There's some damage to the pads and surrounding solder mask on a good few of the pins. I was wondering if anyone had advice on how to approach the repair on this. I'm thinking if I can figure out which pads or traces are damaged, I could repair them with jumper wires. Only thing is I don't have a second working Mega CD 2 to compare with, just some low res pics online.

At the moment I'm thinking that the only way to fix this, would be to pickup a second working one, and probe with a multi-meter....

Anyway, here's pictures of my damaged one, and pictures of a working one which I found online. As you can see I also added copies with inverted colours to see traces better:

Link: https://imgur.com/a/ZHisM

As you can see I also added copies with inverted colours to see traces better.

Any help would be greatly appreciated! Thanks guys

 

Use the schematic?

 

http://gamesx.com/wiki/lib/exe/fetc...2_-_service_manual_number_002_august_1993.pdf

Have fun

 

Yeah thought about trying the schematic, not that confident I can decipher it and figure out exact board locations. There is a 'VA' and a 'VD' numbering on each side of the BIOS chip. Not 100% sure which area of the board this refers to. I'll study it some more and see what I can come up with, thanks guys!

I've also come across this thread which may help me repair this old girl!

https://circuit-board.de/forum/index.php/Thread/21628-Erledigt-Hilfe-bei-Mega-CD-2-BIOS-Reparatur/

 

FIXED IT!!! Wow, didn't think I would but I've got it working. Followed the schematic for every single pin. Turns out it was only pins 21 & 22 that had an issue. Pin 21 trace was lifted and was bridged against the VA2 line (essentially VA1 & VA2 were bridged). Only took 1 hookup wire and she's back in business. Now, to properly install a region free BIOS and recap this baby.

Thanks for the help again. Another one saved from the bin.