Possible capacitor problem with SNES console?

I recently bought Super Nintendo console and at first glance everything seemed to work, although I only quickly tested all games and started playing Super Mario Lost Levels. That game for example works without any issues, it is from All Starts cartridge, I also tried Super Mario 2 and 3, no problems at all. Starwing (Starfox in US) also works fine when I played it.

However, with two games which were included I have problems:

Indycar feat Nigel Mansell and Shaq Fu.

Indycar hangs after Acclaim logo, after several attempts I haven't gotten any further, not to the title screen. Shaq Fu works fine (most of the time) until you should actually get to fight your opponent, it usually hangs before it, black screen. Sometimes it goes further but the graphics are glitched and once it worked fine without any issues at all, but only once so far after several attempts.

I opened the cartridges and cleaned the pins properly, I also wrapped paper towel and used some contact spray and tried to clean the cartridge connector on the console.

Does it sound like there is something wrong with the console itself, capacitors? Because the issues vary a bit (once Shaq Fu worked fine) and pins atleast should be clean that's what I think. However, because Starwing / Fox is one of the most complex cartridges as far as I know (FX chip?) and that works it seems strange.

 

I don't think bad caps in an SNES typically cause games to crash. At least I've never seen that happen. If there are bad capacitors in an SNES usually you'll see issues like overly dark colors, wavy lines in the video, or unusually low audio, but, unless something else is also wrong, the games usually still run normally.

If Shaq Fu did work once, then it sounds like it's either an issue with the game or with the cartridge slot in the console. Even if the cartridge slot looks clean from the exterior, there could still be rust or grime beneath. If it were a CPU or PPU issue, Shaq Fu wouldn't have worked properly even once.

However, since Indycar hasn't worked for you at all, then, assuming the cartridge itself isn't bad, it could still possibly be an issue with the console.

If the serial number is high (like UN25xxx or higher) then the CPU is probably fine, since it'll be CPU-B. It's still possible there could be a PPU issue, but those are less likely to cause games to freeze. Usually with a bad PPU the game will play but the graphics'll just look all screwy.

 

Caps of that vintage need to be replaced but caps aren't the universal scapegoat people like to make them out to be (unless it's a SegaCD or GameGear as those bastards will happily leak and destroy every trace in sight). In a NES you'll lose audio amplification (same with a Genesis I suppose) but I've never had a SNES where the caps failed and I can cleanly point my finger at it.

Get a proper cleaning kit and make sure the SNES has a clean connector first. If it's overly oxidized I could see it working for a short bit then failing.

 

Thank for you responses. There are some updated and corrections. I have managed to get Shaq Fu to the fighting stage but with most attempts graphics are corrupted, player characters are relatively clear, there has been couple times where there are no graphic glitches. Starwing does have some problems, I think renders the game wrong. When you start the game your ship is not under the Training -text but instead upper right corner. I think the viewing angle is also wrong and the ship makes strange dashes down without me even pressing anything. I compared to emulator and YouTube -videos, with my console it runs wrong. Controlling the ship in emulato (with USB pad) was relatively easy, but this console the game is unplayable because all the strangeness going on. No progress with Indycar.

I'm waiting for suitable screwdriver.

Edit: Here is a video about how Starwing behaves:



No buttons pressed while in actual game.

 

Hmm...that complicates things.

If the game acts like you're pressing a button when you're not actually pressing anything, then that's a CPU issue (assuming the controller, control ports, and ribbon cable are all okay).

However, I can't say for certain that you have a bad CPU, since normally if a bad CPU is causing control problems you would have the same issue in all games, yet you seem to only have the control problem with Starfox.

To find out for certain you can swap in some known working control ports and the ribbon cable. If the game still acts like you're pressing buttons when you're not, then it's the CPU.

 

Controller works fine, I have played those Mario games without issues, I've also briefly tried Lethal Weapon and Tintin in Tibet games which seem to work without issues. In Starwing I can control the ship somewhat but it does do those dashes. Also it is strange that when the game starts the ship is in wrong position, also the viewing angle is different. During testing Starwing has not crashed once.

Because some games work, could dirty pins in the cartridge connector cause these kind of issues, or corrosion on motherboard traces etc. ? Some games apparently access different parts of the console chips, ram etc. and have problems while other do not? I find it hard to believe that those games could be faulty, but I guess cartridges do go bad sometimes..

Edit: Nigel Mansell game fails to load even those copyright texts if the console is powered on and Reset is pressed just once. If Reset is pressed and released for example 2 or 3 times in a row then text loads but the game still crashes after Acclaim logo. However, this issue is strange, Shaq Fu and Starwing do not have this issue.

 

It definitely sounds like the console is the problem. I've never personally seen a dirty cartridge slot or corrosion on the board cause issues with controls, but I suppose anything is possible, depending on where specifically the corrosion is located.

Honestly I still can't say for sure what the cause is though. Games crashing or failing to load could happen due to dirt/corrosion in the cartridge slot and the control problems could theoretically also be due to something like bad control ports. Corrupted sprites could also happen due to poor contact. On the other hand, these could also all happen due to a bad CPU, so it's really hard to say for certain what the issue is without actually swapping parts around to rule things out. But whatever the cause is, it does sound like the console itself is the issue.

Sometimes even if the CPU is bad there may still be some games that play totally normally. I've had lots of consoles that play Super Mario World just fine, but behave strangely with other games. If you do open it up and find that you have CPU-B inside then it's more likely that the issue is due to dirt, rust, or something like that, since I've never heard of CPU-B failing.

 

Got the console open and there surely was lots of dust and dirt. I removed and cleaned the cartridge slot and also just in case I reflowed all pins but no difference.

Because some games work, some do not and some do with glitches I suspect that one or more of thr chips have failed, maybe CPU? Seems like I have CPU A. After all this console came with cheap chinese power supply which was also underpowered (1A) altough I don't know how much SNES actually needs and how much the cheap power supply can actually deliver.

I'm pretty sure I could sell everything I bought and get all my money back (perhaps more), then look for a working SNES.

Here is picture of the board/chips:
https://postimg.org/image/r1grzjt4x/

 

Well, the console has now been sitting unused for quite some time and today when I tried it the graphics are all messed up. It cannot even show title screens properly but sound works.

 

Could be bad RAM chips or corroded traces between RAM and PPU chips if you are getting graphics glitches. Test continuity between RAM and PPU.