sega cd corrput internal ram

[douglie007]

I was looking for one too I was trying to find one that would give me 4096 kbit chip to get the max memory the Sega CD cart can do. but I dont know if the BIOS would read it correctly. I was trying to get an emulator to read more in the internal memory, but to no luck

[db Electronics]

No it wasn't any larger. It is exactly the same as the original. You got me thinking now though. Does anyone know of a larger memory chip that would be compatible?

The BIOS only allots so much memory for the internal Backup RAM. Even if there is any space left in the memory map, I'm not aware of a means to indicate to the BIOS the presence of a larger internal memory.

[douglie007]

The BIOS only allots so much memory for the internal Backup RAM. Even if there is any space left in the memory map, I'm not aware of a means to indicate to the BIOS the presence of a larger internal memory.

and that's what I was thinking would happen. Because of the Emulation running the BIOS I was not able increase the memory, it wouldn't work on the hardware. unless there is a custom SCD BIOS that would look for more memory.

[qzack]

Hey qzack I responded to one of your threads regarding this issue a while back. Well I have an update. I did a full cap replacement and it didn't fix my ram problem either. I really didn't expect it to though. Then I tried re flowing the ram chip, again that didn't work. Then I used some chipquick and removed the old ram and soldered in a KM6264BLG-10, which I had researched a month or more ago. Fired up the system and was able to format the ram first try. So far it seems to be working great. Unfortunately I can't test the ram further because the system wont read any discs. I replaced the laser in it at the same time but that didn't seem to help in that regard.

There is a guy on ebay selling the ram chips for about US $10 shipped.


EDIT: Oh yeah thanks db electronics I used your information to check for voltage on IC6 to make sure that was working as well.

And for all you "pics or it didn't happen" people.
http://imgur.com/LOI6vj8
Not my best and I haven't cleaned up the flux, but the system is still essentially useless so...

I appreciate the reply and advice given. I have since gone another route and purchased a model 1 with a good working motherboard. I can now access the ram no problem and played Sonic CD last night with no issues.

[raylyd]

ic 16 is the back up ram ic as i had a bad ram chip.
i just used other and saves was fixed i recommend all sega mega cd/sega cd owners replace batterys and caps even if they are ok.
i do ever sega mega cd multi mega or even sega cd or cdx i do the same as stranded

i found what causes bios background no boot animation ic 5 but can be ic 8/ic8 cd-roms not working even the cd-rom drive works on other ic14 ic15
faulty pcm sound ic10 ic11
this is for 837-8952 boards

i have a stack pile of motherboards saved over the year me just having a mega cd repair addiction werid but i like it.

[SegaSonic91]

i have a stack pile of motherboards saved over the year me just having a mega cd repair addiction werid but i like it.

I am becoming the same