SNES Graphical Glitches

delti90

Cheng's Errand Boy
Joined
Aug 13, 2014
Posts
116
Hopefully this is the right place to post this, but I got a snes off a friend for free and when I'm plugging it in I'm seeing this type of image on pretty much all games:

http://i.imgur.com/6KkpQ8D.jpg

I've cleaned the hell out of the carts and the pins, should I open it up and look for broken traces somewhere? Just curious if this is an issue anyone has encountered before.
 

delti90

Cheng's Errand Boy
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Aug 13, 2014
Posts
116
Bad VRAM or traces leading up to it. Possibly bad PPU chipset

Yeah, at this point that's what I'm thinking. I can't find any bad traces, reflowed the connections on the ppu's and ram just in case but still the same issue. I have a cap kit coming, but I don't expect that'll do much. I figure it's worth a shot though.
 

The Webmiester

Pvt. Picklestein,
Joined
Aug 4, 2001
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420
You could try the ol' press and test method. Press down on the center of the chips like the PPU(s) and see if you get changes on the screen. This is a common method on arcade PCBs when any number of chips could be responsible for video issues.
 

delti90

Cheng's Errand Boy
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Aug 13, 2014
Posts
116
You could try the ol' press and test method. Press down on the center of the chips like the PPU(s) and see if you get changes on the screen. This is a common method on arcade PCBs when any number of chips could be responsible for video issues.

I actually did try that, didn't seem to help. In the end I found a snes with a broken power jack on craigslist for $25 so I got that and pulled the jack off of this one, as well as a bunch of other stuff for spare parts :P. Unfortunately the cap kit didn't help, I wasn't really expecting it to though.
 

HMG

H = Heinously, M = Massive, G = Gonad,
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Bad VRAM or bad S-PPU chips (older SNES boards have two S-PPU cores). You could try replacing the VRAM, it's just Static RAM. Broken S-PPU chips are unrepairable.

If you already have a replacement SNES console, the best thing to do is prevent future chip death by improving the power filtering. The SNES has almost none and is at the mercy of your power supply and local power grid. Put a 220uF 16v cap on the ground and output of the 7805. Most SNES consoles have an empty spot for a big capacitor at the back near the power/AV ports. Put a 1000uF 16v cap there. Even that will help a lot.
 

delti90

Cheng's Errand Boy
Joined
Aug 13, 2014
Posts
116
Bad VRAM or bad S-PPU chips (older SNES boards have two S-PPU cores). You could try replacing the VRAM, it's just Static RAM. Broken S-PPU chips are unrepairable.

If you already have a replacement SNES console, the best thing to do is prevent future chip death by improving the power filtering. The SNES has almost none and is at the mercy of your power supply and local power grid. Put a 220uF 16v cap on the ground and output of the 7805. Most SNES consoles have an empty spot for a big capacitor at the back near the power/AV ports. Put a 1000uF 16v cap there. Even that will help a lot.

That's for the suggestion. I'll get some of those caps for my two new snes'
 

HMG

H = Heinously, M = Massive, G = Gonad,
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You could also get a quality surge protector for your SNES as well.
 

Apocalypse

Edo Express Delivery Guy
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Sep 16, 2015
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331
Bad VRAM or bad S-PPU chips (older SNES boards have two S-PPU cores). You could try replacing the VRAM, it's just Static RAM. Broken S-PPU chips are unrepairable.
Correct. I had exactly the same problem. In fact my very first SNES which I played for 20 years just died after 7 years not using it. And when I opened it I discovered that the power supply part of the board has already been repaired ages ago (in fact before I bought it second hand 20 years ago).
I replaced both the VRAM and PPU from an uncased motherboard laying around.
I guess the initial power supply problem (possibly overvoltage) has reduced chips lifetime.
 

MtothaJ

Host for Orochi
Joined
Apr 15, 2013
Posts
754
Bad VRAM or bad S-PPU chips (older SNES boards have two S-PPU cores). You could try replacing the VRAM, it's just Static RAM. Broken S-PPU chips are unrepairable.

If you already have a replacement SNES console, the best thing to do is prevent future chip death by improving the power filtering. The SNES has almost none and is at the mercy of your power supply and local power grid. Put a 220uF 16v cap on the ground and output of the 7805. Most SNES consoles have an empty spot for a big capacitor at the back near the power/AV ports. Put a 1000uF 16v cap there. Even that will help a lot.

Just added these two caps to a SNES Mini as it was pretty bad at blowing fuses. I noticed there are two unpopulated solder pads right next to where the fuse is on the Mini, wondering whether there is something missing there also.
 

Unessential

New Challenger
Joined
Sep 23, 2015
Posts
25
You could try the ol' press and test method. Press down on the center of the chips like the PPU(s) and see if you get changes on the screen. This is a common method on arcade PCBs when any number of chips could be responsible for video issues.


Interesting, I'm assuming that would work with arcade boards too? May be useful for a quick and dirty diagnosis when tools and equipment aren't available....
 
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