nesdev.org

Hey,

Thought this would be the best forum for this. I have a super nintendo that previously worked fine
but now when you start up a cartridge it plays for about a minute then the graphics get all garbled
and it hangs\crashes. I have no clue what could be wrong. I thought it might be the voltage regulator
maybe (??) but I figured I'd toss this post up first before messing about if someone else on the forum
has delt with a similar issue before.

Cheers,

Shawn

You should measure your regulator output after it hangs up. Might be heat related so you should also feel the chips for being too hot... Maybe a bad cap on the power section..... Maybe your power brick is failing too.

After all these, it could be anything... Hope this helps.

Markfrizb wrote:You should measure your regulator output after it hangs up. Might be heat related so you should also feel the chips for being too hot... Maybe a bad cap on the power section..... Maybe your power brick is failing too.

After all these, it could be anything... Hope this helps.

The regulator is gonna be my first suspect to interrogate. After that I'll take a look at the caps. God I hate cap jobs cause it's damn near impossible to find the culprit unless one totally fries so you end up replacing half or more of the damn things. I'd end up probing the whole damn motherboard to find one fried cap with my luck.

Yeah, but 20 year old caps ought to be replaced anyways.... They are way beyond their life expectancy.

wasn't the regulator. 8 zillion little caps are looking very overwhelming right now.

After it stops working, is anything particularly hot?

nintendo2600 wrote:wasn't the regulator. 8 zillion little caps are looking very overwhelming right now.

Only the electrolytic caps I was referring to.

Does it happen on every game? My old SNES had a similar issue where graphics would go distorted only on certain games like Tales of Phantasia or DKC. After a bunch of digging around and asking on different forums it was figured that my PPU or VRAM were probably dying...so I just bought another system.

Wish I could help with this kind of thing, but I actually have a bizzare console problem myself. I have one SNES that works perfectly fine with every game I own except Dragon View, which loads with a garbled power-up screen and "loses" graphics in specific ways while playing (eg/ everything is fine until you open the menu in a dungeon, after which everything except your player and the status bar goes black and doesn't seem to come back until you change regions or something). I've tested it over and over and it's perfectly reproducible, no other game seems to have problems and I've confirmed for certain it's not a problem with the cartridge either.

The game seems to play fine, it's just the screen that's messed up. Given that the title screen loads with some tiles correct and some not, my best guess is maybe one bit of a VRAM address bus is broken but I really don't have a clue. If it's possible to diagnose something like this and anyone knows how, I'd be glad to waste a day poking around to figure it out.

getafixx wrote:Does it happen on every game? My old SNES had a similar issue where graphics would go distorted only on certain games like Tales of Phantasia or DKC. After a bunch of digging around and asking on different forums it was figured that my PPU or VRAM were probably dying...so I just bought another system.

I doubt his problem vram or ppu related. Even though strange tiles and things go on the screen, his SNES actually crashes, while if there were a problem with either of those, the game would at worst show a black screen, but you would still be able to interact with it. I'm curious, but does the audio get messed up too? usually if the game crashes, the audio still plays because it is almost a separate system from the rest of the SNES (I think it's only connected by 4 busses?) However, if there was a power supply problem, I imagine both would shut off or do weird stuff. (I'm no expert though.)

If the PPU stops generating NMIs, it could cause games to freeze.

To narrow down whether it's an audio problem, try one of the games whose sound drivers rely on constant communication over those four I/O ports.

getafixx wrote:...so I just bought another system.

Which means you never got to know for sure what the problem was.

tokumaru wrote:

getafixx wrote:...so I just bought another system.

Which means you never got to know for sure what the problem was.

Something similar happened to me. Our old family SNES started not working properly with certain games. F-Zero had screwed-up Mode 7 maps, so that you'd be driving on city instead of track, and would thus lose health and eventually blow up. Super Mario Kart was perfectly playable, but the Mode 7 graphics at the victory screen (the fish and the congrats message) were not there. Yoshi's Island had garbled backgrounds with wrong tiles and colours, but was also playable. Super R-Type worked perfectly as far as I could tell. Super Metroid looked fine until you realized that the map didn't show up, and that certain powerups were missing, resulting in a dead end.

So I bought a replacement.

My hardware expertise is limited to the lab portion of an electrical engineering lite course I took as part of my mechanical engineering undergrad over a decade ago, so I haven't even opened the unit up to see if anything obvious is wrong (leaky cap or some such)... It'd be cool to get it fixed at some point, I guess, if it's possible...

tepples wrote:If the PPU stops generating NMIs, it could cause games to freeze.

Oh yeah... (I guess vram still isn't an issue, unless I'm not thinking again.)

Also, since I have no kind of electrical engineering background, what are "caps"? are they these things? What do they do? What do they contain, some sort of battery acid? (I looked up electronic caps on Google, but I just got some sort of company.)

Capacitors.