NES mangled display - cause?

[Steve030]

Hi guys,

I am attempting to repair a NES that has a display output like this:
https://drive.google.com/file/d/18tcilu ... sp=sharing

I have done the following:
- re-cap both the board and modulator
- re-flow solder on cpu and ppu
- clean and straighten pins of the cart connector

But still the issue persists. Any advice welcome. Thank you.

[Steve030]

Just a small update - I just swapped the cart connector with a 'known good' connector and the issue persists. Any other ideas on what I could look at appreciated.

[Sumez]

Wow that's something else. I'm impressed you've gone as far as to replacing all caps and reflown solders.

It's hard to see what this is supposed to be a picture of, but if sprites and backgrounds are equally effected by the garble, I guess the PPU is just dead.
If only the background tiles are affected, there's a chance it could be the video RAM IC, or some of the lines going to it.

[SCARTicus]

You have to blow into the NES cartridge before inserting it or this will happen.

[Steve030]

Wow that's something else. I'm impressed you've gone as far as to replacing all caps and reflown solders.

It's hard to see what this is supposed to be a picture of, but if sprites and backgrounds are equally effected by the garble, I guess the PPU is just dead.
If only the background tiles are affected, there's a chance it could be the video RAM IC, or some of the lines going to it.

Yeah its SMB3, both sprites and bg equally bad. After doing some 'google research' I am also thinking it must be the PPU. The CPU is obviously fine as the game is actually playing and moving in the background lol

[Steve030]

You have to blow into the NES cartridge before inserting it or this will happen.

I put the cart slot into an ultra-sonic cleaner and also leveled-up the pins individually. And the game cart itself is brand new. And I tried another cart slot all-together, same issues.

[Sumez]

Yeah outside of outside interference (I guess caps, etc.) I don't really see how both BG and sprites can be affected like that unless something's wrong with the PPU internals. Unfortunately I've heard of quite a few NES PPUs that have died by now.

[BareKnuckleRoo]

That's some serious artifacting that doesn't look like what you'd get from a bad pin connection. If you're diligent and knowledgable enough about it to resolder everything and clean everything, as Sumez suggests I'd look at actual hardware failure as the cause. Looks like Legend of Zelda to me if I'm not mistaken?

https://www.arcadecomponents.com/catalo ... 583135.htm Appears to have replacement parts but are currently on backorder.

https://www.reddit.com/r/nes/comments/9 ... placement/ Suggests that working clones exist if you can't get a hold of an original PPU.

[Steve030]

That's some serious artifacting that doesn't look like what you'd get from a bad pin connection. If you're diligent and knowledgable enough about it to resolder everything and clean everything, as Sumez suggests I'd look at actual hardware failure as the cause. Looks like Legend of Zelda to me if I'm not mistaken?

https://www.arcadecomponents.com/catalo ... 583135.htm Appears to have replacement parts but are currently on backorder.

https://www.reddit.com/r/nes/comments/9 ... placement/ Suggests that working clones exist if you can't get a hold of an original PPU.

SMB3, cheers for the links. Might checkout the clone chips.