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goombakid
11-07-2014, 05:30 PM
I got a couple of region free BIOS's burned as a trade. I got the M1 BIOS in and working perfect.

I was trying to get the M2 BIOS swapped out today, but I hit a snag. There's a possibility that I may have messed up a pad while desoldering the BIOS.

http://img.photobucket.com/albums/v246/ryo808/Mobile%20Uploads/6db28d96-eeec-43a0-8bf0-be442451e2d9_zpsb0e41312.jpg

Sorry, it was hard to snap a clear pic on my phone while holding it up to the light.

The circled area is where I may have messed up. If I'm looking at that right, it looks like that pin and the pin to the left of it connect. Anyone familiar with this can confirm?

shadowkn55
11-07-2014, 05:32 PM
I'm not familiar with the pinout of the bios but if you have the part number of the eprom that you plan to drop in, that would easily help you solve the problem.

goombakid
11-07-2014, 05:38 PM
I'm not familiar with the pinout of the bios but if you have the part number of the eprom that you plan to drop in, that would easily help you solve the problem.

It's an M27C1024-10F1. Datasheet says it's pins 39 and 40, P and Vcc respectively.

shadowkn55
11-07-2014, 05:42 PM
Those three pins should probably tied to VCC. Pin 40 is VCC, Pin 39 is /P which is normally tied to VCC or GND but since it sits right next to the VCC pin, they are tied together. Pin 38 is NC so it can be totally disconnected from everything or tied to VCC for convenience when using higher capacity roms.

goombakid
11-07-2014, 05:46 PM
Pin 38's pad is fine, so I'm not gonna worry about that. It was just pin 39 that looks like it was damaged.

Thanks for the help, Quan. Really appreciate it. If you wanna tackle the Samsung Encoder for the M2 Genesis, lemme know.

shadowkn55
11-07-2014, 07:19 PM
Pin 38's pad is fine, so I'm not gonna worry about that. It was just pin 39 that looks like it was damaged.

Thanks for the help, Quan. Really appreciate it. If you wanna tackle the Samsung Encoder for the M2 Genesis, lemme know.

I'll probably give it a shot on a system I can find locally. A model 2 with a samsung encoder isn't the hardest to find on the cheap.

goombakid
11-07-2014, 11:19 PM
Update: I soldered in a 40 pin socket, bridged pins 39 and 40 with a bit of wire, put the BIOS in. Works perfect!

Thanks again!