Won't Load Game After Sega Logo (Even After New Cart Slot and Re-Cap)

[baceman007]

Hello everyone. I have a Sega Genesis Model 2 (more specifically an mk-1631). It was having problems loading known good games past the Sega Logo. These games load on two other Genesis systems that I have. So:

1. I tried to re-tension the slot. That didn't work, and the carts were still loose, so.

2. I soldered in a new cartridge slot, did a continuity test on all of the pins (it passed) so I tried again. Still, wouldn't pass the Sega screen.

3. I soldered in a new reset button at this point for good measure. The old one had a worn out rubber cap. That works correctly now.

4. So, I tested the capacitors, some were bad, so I re-capped the board. All new capacitors passed a capacitance test and the new connections passed a continuity test. So I tried again. Same issue. Won't pass the Sega screen on known good cartridges.

My question is, what do I do now since, in theory, there isn't a problem with the cartridges, cartridge slot, or capacitors?

[Taijigamer]

Do you have access to an O-scope? Maybe it's a problem with the 7805 regulator or a bad RAM chip.

[Jeremy Popp]

Hello everyone. I have a Sega Genesis Model 2 (more specifically an mk-1631). It was having problems loading known good games past the Sega Logo. These games load on two other Genesis systems that I have. So:

1. I tried to re-tension the slot. That didn't work, and the carts were still loose, so.

2. I soldered in a new cartridge slot, did a continuity test on all of the pins (it passed) so I tried again. Still, wouldn't pass the Sega screen.

3. I soldered in a new reset button at this point for good measure. The old one had a worn out rubber cap. That works correctly now.

4. So, I tested the capacitors, some were bad, so I re-capped the board. All new capacitors passed a capacitance test and the new connections passed a continuity test. So I tried again. Same issue. Won't pass the Sega screen on known good cartridges.

My question is, what do I do now since, in theory, there isn't a problem with the cartridges, cartridge slot, or capacitors?

Man, that's a lot of effort for a Genesis - for your sake, I hope you get it working. I've actually repaired 2 model 2 genesis consoles with this issue, and both times it was a bad trace on the motherboard that went to the cartridge slot. Sounds like you may have already looked that area over, but on both of mine I could see visual proof of some sort of corrosion on the board, and lo and behold one of the traces was bad. Good luck.

[baceman007]

Thanks for your reply guys. Very helpful.
Taijigamer, I can get my hands on an O-Scope if need be. It's also on my Christmas list for my new electronics workbench! Yeah!
Jeremy Popp, I took a much closer look at the board and although everything around the slot checks out ok, I found some goop and some black stuff around the SRAM (KM6264BL-10). Alcohol did not work, so I might try Brasso next unless you have any other suggestions. I am hoping the black parts are not breaks in the traces and can be cleaned up. Otherwise, I guess I'm soldering in some SRAM and trying to redo the traces in that area. Here is a pic. The damage I'm talking about is closest to the rest button.