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View Full Version : NES VRAM Replacement Needed


megasdkirby
07-23-2021, 07:52 PM
Anyone know where I can obtain online a replacement VRAM for the NES? Current one is the Sony CXK5816SPS-15L. Any compatible RAM is welcome.

When turned on, it would blink to a green screen (checked all connections and cleaned all parts and now it doesn't blink anymore). It now boots the game every time. However, all games have graphical glitches or missing graphics. In some games, the main character does not appear on screen, but the rest is visible. Other times, I see numbers and garbled graphics on the screen while the game plays. So my guess is the VRAM. Can't be the dirty contacts or not making contact since I've troubleshooted that for hours and all outcomes are the same, even with known good.

Any ideas? Thanks!
Gameguy
07-23-2021, 08:26 PM
This sounds like the exact issue I had with an NES console years ago, and it wasn't the connector as games basically booted up right away every time. I ended up selling the console for parts as I couldn't figure out how to repair it, if you figure it out I'd like to know what the cause actually is. I assumed it was the graphics encoder but I could be way off.
megasdkirby
07-23-2021, 11:13 PM
Someone on Facebook said that there is a good chance it's not the VRAM or the WRAM, but the PPU or even the CPU. Problem is, if it is, I need to get them from AliExpress. Wish there was a US seller, though.

I may also create a test NES if I get another "as is" console from eBay or locally. That would help quite a bit.

I will let you know the progress!
Gameguy
07-24-2021, 01:03 AM
Thanks, I'll keep checking with your progress. I wish I could be more helpful.

If it's a problem with the CPU, maybe you could look towards Adrian's Digital Basement on youtube for advise? He seems to diagnose and repair vintage 8-bit computers with similar issues and ends up replacing chips on a regular basis, even just figuring out how to diagnose defective chips might be helpful in this case. I just remember he had defective CPUs in the past that he needed to replace. I think he has a website with contact information as well.