SNES with SuperCIC couldn't past games' title screen. Now black screen

Hi! So I bought a PAL SNES, modded it, and it's been working fine for about 3 months. But, today when I unplugged it from my HDTV to try it on a CRT, the game (kiki kaikai) booted and played fine the first couple of times. Then suddenly! the intro music is playing more slowly than it's supposed to. I think the animation too. I didn't think too much of it, and connected the SNES to my HDTV again (power off).

Then later this day, I tried to play Super Street Fighter 2. But it would not boot past the initial text. Neighter would SF2 turbo. Super Mario All-Stars booted with weird coin and jump samples, and stops before the title screen. This guy had the same problem with the audio on All-Stars: http://youtu.be/Dnfr6T3gWiQ
Now though, I can't get All-Stars to work just a black screen. The only games that boot (SSF2, SF2Turbo), only show the copyright screen, then stops there.

-fuse looks good, and tested for continuity
-snes is PAL snsp-cpu-01 2PPU
-in PAL mode I get ~5V on the ppu pins
-the cart slot is clean
-tested another cartridge slot
-SuperCIC seems to work; it iterates the LED colors and will change mode after 9 seconds. All connections are still good.
-capacitators look good -- EDIT: nope, on closer inspection, capacitator C59 by the rf is bad.. It has leaked, and broken C60's solder pad. What's its purpose? I replaced both caps.
-have disassembled the board and heat sinks. The only evident damage is C59 and C60.
-tried 2 working power adapters
-tried 2 svid cables, and 1 composite.
-connecting to TV with s-video via a scart plug adapter with input/output switch on it. Would this, if the switch had been in the wrong position, have damaged the SNES?
-how should I troubleshoot this?
Thanks!

It looks like C59 damaged a solder pad for C60.. Anyone know an alternate point on the underside of the board for the pad that's closest to C59? Can't seem to find it myself

 

It looks like C60 and C59 are connected to the 12v circuit for the multi out connector. The pad on C60 that is closest to C59 is connected to GND and the other pad of C60 is connected to R72 on the underside of the board and also the emitter of a transistor next to R72 that doesn't seem to be labeled.

C59 is connected directly to the AC supply of the bridge rectifier and the collector of the transistor mentioned above. I'm not sure exactly how it all fits together yet but unless you were using an RGB cable that circuit would not affect anything. It sounds more like there is either a short circuit or there has been and it has damaged something else.

EDIT: Come to think of it, I'm not sure if the component next to R72 is actually a transistor or possibly a switching diode labeled DA13 although it doesn't really matter in your case, I just thought I'd mention it for correctness.

 

Thanks for looking into it, kel!
I've replaced C59 with a radial cap rated 10uF/100V. I replaced C60 with 10uF/50V, and soldered the negative side to GND on the multi-out because of the corroded pad. All the other pads were good.
Doing this made no difference, though
--updated first post.

 

It might help to replace all electrolytic caps in the SNES. If one has gone bad then others are probably not far behind even if they don't show any signs. You might find when you remove others that they have started to leak underneath. Bad caps are apparently a common thing in the SNES and can cause all sorts of problems.

 

I seem to have fixed it! C59 had corroded the pad on C60, and also 2 traces; 1 leading to the cartridge connector, and the other to the expansion port (but also the cart.. apparently they're connected). Was barely visible, but checked every trace and via near C59.
Yeah it's probably a good idea to replace all the caps after googling a fair bit, it seems C59 is quite prone to failure, and was a component Nintendo replaced often, and then slapped a C59 sticker underneath the console.

 

Good to hear you managed to fix it. Now that you mention it the traces around C59 on my board look a bit brown and discolored. Although it is a scrap board I think I will remove it and check for corrosion out of curiosity.

It's interesting that C59 is prone to failure. I wonder if it has something to do with it being connected to an AC circuit? I didn't think that polarized capacitors were meant to be used on AC circuits?

 

On the schematic I am looking at, C59 is just an output cap from the video encoder.

Nothing to do with AC. if you mean the SNES being AC - thats not the case. The AC from the PSU is immediately rectified to DC pretty much as soon as it enters the console.

 

Unless you have some unreleased schematics then the ones floating around are from the US SNES or JP SF. The composite sync out on the multi out connector gives it away.

Apparently before it is rectified it is also tapped for the +12v circuit of the multi out connector, which includes C59 in series. I'm not sure exactly why?

 

tv wont take AC.

The NTSC consoles are DC, not AC

They have a DC psu and no rectifier

 

Never mind, I can see we are not getting anywhere here

 

Not sure what you are talking about...

The TV will not take an AC signal for the 12v. If you are looking at NTSC schematics, its because those consoles are not AC at all - no AC power supply, no recitifier - the schematic is different.

Its not possible that its using the AC signal before its being rectifed. In all the PAL consoles I have in front of me, the very first component from the AC jack is a rectifying bridge.

 

Ok, let me try to emphasis what I was talking about.

Apparently before the AC supply is rectified it is also tapped for the +12v circuit of the multi out connector (not the +12v pin of the multi out connector), which includes but is not limited to C59 in series. I'm not exactly sure how this circuit works but there are other components after C59 like a switching diode connected: AC supply-C59 to cathode/anode then DC regulator input to anode and 12v+ multi out pin to cathode via a 1k resistor. There is also a zener diode between the 1k resistor and the multi out pin for protection. Obviously the +12v multi out pin does not output AC, I was never talking about the +12v ouput of the SNES. I was talking about the +12v circuit of the SNES which definitely does connect to the AC supply at some point and on that small part of the AC circuit is C59 in series which is what puzzled me. A polarized electrolytic cap connected to an AC supply doesn't seem right.

I never looked at any schematics to trace this circuit. I only looked at schematics once you referred to them to verify that the only ones online are actually NTSC schematics which was why you thought C59 was just an output cap from the video encoder.

 

yeah, I am still not seeing that on the consoles I have.

What board revision are you looking at?

How are you tracing this? with a multimeter or by eye? If you are probing with a multimeter from the AC jack, its going to still go through the bridge and make it look like its connected when its not.

If by eye, interested to see pictures of that board revision.

If using a multimeter, take the bridge out and try again.

 

The board I've been looking at is a SNSP-CPU-01.

If you remove the heat sink you will see a large trace running from one of the inputs of the bridge rectifier to C59.

I have also traced the same connection on a 1-chip console ealier today with a multimeter and it was the same although I didn't really take note of the capacitor number on the 1-chip so it may have been different.

 

I have a mini and phat 1chip here and thats not how it is at all. If you probe with a multimeter on this onechip, the only reason its showing as connected from the AC side of the bridge is because its going through the bridge and connected that way.

here are some pictures:

This is the input of the bridge to C59:
https://dl.dropboxusercontent.com/u/28488139/IMG_20140717_212154.jpg

This is connected (but its going through the bridge and connected on the DC side)

This is the bridge removed and probing the same points (and not connected):
https://dl.dropboxusercontent.com/u/28488139/IMG_20140717_212300.jpg

This is from the DC side of the bridge and you can see this is where the connection is:
https://dl.dropboxusercontent.com/u/28488139/IMG_20140717_212308.jpg

 

I am certain that I'm not confusing the voltage regulator with the bridge rectifier because the switching diode on the circuit is connected to both (cathode/anode is connected to input of the bridge rectifier and the anode is connected to the input of the voltage regulator.

My battery just died on my camera while I was trying to take a photo of the connection. You can't miss it if you see it. I could imagine that it would be a bit harder to see or trace on a 1-chip or mini due to the bridge rectifier being made of stand alone diodes instead of the packaged type on the older revisions but the connection is still the same.

EDIT: Hold on a minute the mini doesn't have a bridge rectifier. that one got past me, not sure why you mentioned the mini.

 

The rectifier isnt stand alone diodes on a PAL 1chip. I have posted pictures above.

Edit:

Pointless talking about the mini, as it uses DC anyway.

Edit2:

Just checking something, as I could be being doing something very dumb....

Edit3:

Right, my confusion was caused by 1chip rectifier vs "normal" ones. You are quite right that the cap is connected to the AC supply. However, its a non polarised cap - so its not a problem anyway.

The OP should check that hes not fitted a polarised cap in C59, as thats not correct. It must be non polarised (which is in both the consoles infront of me). I cant seem to put my hands on any of the non 1chip consoles atm - which would have made this conversation much less painful =/



In short to anyone reading, kel was quite right - I got confused by the different rectifier in the 1chip consoles. However, the original cap is non polarised for C59 on 1chip consoles and should be replaced with the same type (or in older consoles, swap the polarised for non polarised.)

 

Not to pick nits or anything as I know it doesn't matter connection wise but that is not the bridge rectifier. The bridge rectifier is D2,D3,D4,D5. that other component on your pictures is a choke.

You are correct, it should be a non polarized cap. It seems that Nintendo missed that memo when it came to designing/assembling the older revisions which is probably why C59 leaks in the end and causes problems like the OP's.

Yeah, I could imagine it would be a lot harder to see on the 1-chip. I only knew where to trace straight away on my 1-CHIP because I had already traced it on the SNSP-CPU-01.

 

Yes, I know that now after you mentioning the rectifier isnt a packaged one. As I have not looked at the packaged rectifier in the older consoles for awhile, I got them confused - which is what caused this mess

I use ones that look like this:


which looks similar when you have not used one for awhile. Sorry for all the confusion!

On a side note, I dont seem to find any reference to this flaw with my googling. But this should definitely be swapped out on any consoles with a polarised cap in there. So at least there was something gained from this!

 

Oh and thanks for clearing up the confusion about C59 needing to be non polarized, it was worth all the debating just for that. It had me puzzled and is probably the cause of a few dead SNES consoles like the OP's. Next time someone comes along with an old revision SNES with similar problems we will know were to point them.

EDIT: You beat me to it with your edit on your last post but yeah I could see how the choke and the rectifier in your picture could be easily confused.