Super Nintendo (SNES) powering but no video signal

[Stufio]

EDIT: POWER SUPPLY WAS THE ISSUE!
I drove 30 minutes or so to the nearest game store and asked if I could test my SNES with their cables, games, controllers, etc. The SNES powered on and worked just fine! When I tried my power supply, but their TV and AV cable, it would power but not show any video (the same symptoms I was having at home). So, if anyone sees this thread and has the same problems it is POSSIBLE that the PSU can power the SNES but not allow for video output. I have bought another power supply online and should receive it in a few days. Thanks to everyone for their help with this issue!

Let me start by saying I've looked up the symptoms of my SNES all over the internet and can't find a definite answer.

Here's my situation: I recently got my childhood SNES out of storage and plugged it up to my TV. When I powered it on, the red power indicator light lit up, but I received no signal at all on the TV. That DOES NOT mean that I received a 'black screen' as I have read about others seeing. My TV actually has a "no signal" message, meaning it's not receiving anything. I also have a video processor (nothing amazing, but it does the job) that I tried to plug it into, and it showed no signal coming into it as well. Here's everything that I have tested:

1. 3 different cables (Composite, S-Video, and HDRetrovision Component cables)
2. Different consoles (N64, GameCube) to make sure the inputs on the TV and video processor are both working
3. Cleaned the pins on the 62-pin connector and all of my games

After taking the SNES apart to clean the pins, I still received no signal. I took the SNES apart again and accidentally blew the pico fuse on the board (not hard to replace, but haven't done so yet). At that point, I figured "I'd rather buy another SNES that I know works than replace the fuse and still receive no signal" so I started looking for another SNES. I bought one the other day for $30 (a great deal) but it had no cables of any kind. I bought it online and the listing showed pictures of it plugged in and working. When I got the SNES, it has the same symptoms that my original SNES had: it powers on, but I receive no signal on the TV with different cables, through the video processor, or even after cleaning the pins.

Here's my thought process at this point: the odds of BOTH SNESs having the same issue (especially when I just saw a picture of the 'new' one working, are slim. The only other variable that I can possibly think of is the power supply. It is my original childhood power supply. When I used my multimeter on the power supply (black probe in the barrel, red probe on the outside of the barrel), I got a reading of 18V. Isn't that a little high for a 10V power supply? I don't know anyone else who has a SNES, so I don't have any other power supplies to test with. If it IS the power supply that's the problem, the new SNES should work and I could replace the fuse on my original SNES and it should work too.

So, HERE ARE MY QUESTIONS: Can a power supply go 'bad' and produce too much voltage? If so, is it remotely possible that too much voltage would allow the SNES to power on, but not produce any video at all?

I will gladly buy another power supply, but I'd rather be reasonably sure that it is the issue before dropping $15-20 on it.

Thank you for your help.

[ZellSF]

From what Google tells me, SNES should theoretically handle 18v as that's the maximum safe voltage for the voltage regulator... but:

1: PSU rated for 10v outputting 18v is obviously faulty and who knows what else it could be doing wrong.
2: you don't want to be anywhere near that.

It's also the only thing you haven't ruled out (except the controller).

[Stufio]

From what Google tells me, SNES should theoretically handle 18v as that's the maximum safe voltage for the voltage regulator... but:

1: PSU rated for 10v outputting 18v is obviously faulty and who knows what else it could be doing wrong.
2: you don't want to be anywhere near that.

It's also the only thing you haven't ruled out (except the controller).

Do you have any idea if the power supply could possibly affect the video output in that way? It just seems very unlikely to me that the power supply would cause no video output. As you said, though, it's the only thing I can think of that I haven't rules out.

[kamiboy]

A power supply can go bad, indeed. Usually the culprits are aging capacitors.

[ApolloBoy]

You're getting 18V from the power supply because you're measuring it without a load. In order to measure what it's actually putting out you'd have to check the input voltage on the 7805.

[Stufio]

You're getting 18V from the power supply because you're measuring it without a load. In order to measure what it's actually putting out you'd have to check the input voltage on the 7805.

That makes sense. Is it possible that a bad power supply could prevent video from being output? It's the only variable I haven't been able to test...

[accaris]

You're getting 18V from the power supply because you're measuring it without a load. In order to measure what it's actually putting out you'd have to check the input voltage on the 7805.

That makes sense. Is it possible that a bad power supply could prevent video from being output? It's the only variable I haven't been able to test...

There are a few things that can cause no video signal on a SNES. In order of most likely to least likely, they are:

1) Caps not holding a charge or holding a weak charge. Caps need to be replaced.
2) Corrosion somewhere in the cartridge connector or at the base of the pins where they meet the motherboard.
3) Broken traces between the PPU and the rest of the board.
4) VRAM chip has gone bad and needs to be replaced.
5) PPU itself has gone bad and you'll have to replace the SNES.

It's almost never related to the power brick. That doesn't mean it ISN'T the power brick, since you've tried two consoles and it happens on both of them. I've just never heard of it happening.

[ZellSF]

You're getting 18V from the power supply because you're measuring it without a load. In order to measure what it's actually putting out you'd have to check the input voltage on the 7805.

Oops, didn't know the SNES had an unregulated power supply.

Question though: you say no video signal, is there any audio signal? Response to controller input?

[Stufio]

You're getting 18V from the power supply because you're measuring it without a load. In order to measure what it's actually putting out you'd have to check the input voltage on the 7805.

That makes sense. Is it possible that a bad power supply could prevent video from being output? It's the only variable I haven't been able to test...

There are a few things that can cause no video signal on a SNES. In order of most likely to least likely, they are:

1) Caps not holding a charge or holding a weak charge. Caps need to be replaced.
2) Corrosion somewhere in the cartridge connector or at the base of the pins where they meet the motherboard.
3) Broken traces between the PPU and the rest of the board.
4) VRAM chip has gone bad and needs to be replaced.
5) PPU itself has gone bad and you'll have to replace the SNES.

It's almost never related to the power brick. That doesn't mean it ISN'T the power brick, since you've tried two consoles and it happens on both of them. I've just never heard of it happening.

Thanks for the info. It is totally POSSIBLE that both SNESs are having the same problem, I just feel that is not PROBABLE. Since the listing I bought it from online showed pictures of the 'new' SNES working correctly, I feel that it has to be some factor in my own setup (TV, video processor, cables, power brick, etc.).

Is there a way to test the capacitors? I am not experienced at all with circuitry (I don't even own a soldering iron), but I do own a multimeter.

[Stufio]

You're getting 18V from the power supply because you're measuring it without a load. In order to measure what it's actually putting out you'd have to check the input voltage on the 7805.

Oops, didn't know the SNES had an unregulated power supply.

Question though: you say no video signal, is there any audio signal? Response to controller input?

I have not gotten any audio at all or any response to controller input.

[mvsfan]

I had an snes with the same symptoms once that had "no signal" on my DLP tv, but would show a fuzzy black and white image with a black line through the middle of it on a CRT tv.

It turned out to be a bad capacitor in my power supply. I replaced the cap and everything worked great, and after that i went ahead and also replaced the caps in the console.

[Stufio]

I had an snes with the same symptoms once that had "no signal" on my DLP tv, but would show a fuzzy black and white image with a black line through the middle of it on a CRT tv.

It turned out to be a bad capacitor in my power supply. I replaced the cap and everything worked great, and after that i went ahead and also replaced the caps in the console.

So, in your case, the power supply actually did affect video output. Interesting. How did you check the capacitor and figure out it needed to be replaced?

[Guspaz]

I had an snes with the same symptoms once that had "no signal" on my DLP tv, but would show a fuzzy black and white image with a black line through the middle of it on a CRT tv.

It turned out to be a bad capacitor in my power supply. I replaced the cap and everything worked great, and after that i went ahead and also replaced the caps in the console.

So, in your case, the power supply actually did affect video output. Interesting. How did you check the capacitor and figure out it needed to be replaced?

Capacitors can't be tested in-circuit, so all you've got to go on is visual inspection. It's why people typically just replace all the capacitors rather than individual ones: if you were going to pull each capacitor out to test it, you might as well just replace each one with a brand new one anyhow.

[mvsfan]

because when i opened the power supply the capacitor was leaking bad. I had to clean the gunk off the transformer and inside of the case first before i replaced it.

[mvsfan]

I just thought of something else that you may be getting ahead of yourself on. Some newer tvs do NOT like 240p and will just say no signal if thats the case.

Its why i always like to test old systems on a CRT. it wont tell you that you have no signal unless theres no sync. on a crt you can usually tell if a console is half way working because most of the time you will still get something on screen. whereas on a flatscreen if its not working somewhat it will always say no signal.

it also means there may be nothing wrong with your snes, just like the seller said.

[Stufio]

I just thought of something else that you may be getting ahead of yourself on. Some newer tvs do NOT like 240p and will just say no signal if thats the case.

Its why i always like to test old systems on a CRT. it wont tell you that you have no signal unless theres no sync. on a crt you can usually tell if a console is half way working because most of the time you will still get something on screen. whereas on a flatscreen if its not working somewhat it will always say no signal.

it also means there may be nothing wrong with your snes, just like the seller said.

That is an interesting thought. I don't think it is the case here though, as the TV recognizes my NES, Genesis, and N64 correctly. I feel like I've tested every testable variable except a new power supply, which I have yet to purchase.

[bobrocks95]

I just thought of something else that you may be getting ahead of yourself on. Some newer tvs do NOT like 240p and will just say no signal if thats the case.

Its why i always like to test old systems on a CRT. it wont tell you that you have no signal unless theres no sync. on a crt you can usually tell if a console is half way working because most of the time you will still get something on screen. whereas on a flatscreen if its not working somewhat it will always say no signal.

it also means there may be nothing wrong with your snes, just like the seller said.

That is an interesting thought. I don't think it is the case here though, as the TV recognizes my NES, Genesis, and N64 correctly. I feel like I've tested every testable variable except a new power supply, which I have yet to purchase.

Is your NES, Genesis, or N64 connected through component video? I'm guessing not.

EDIT: To clarify, HDTVs sometimes don't accept 240p through the component connector. ALL will support 240p through a composite connection since 15kHz is the max res that a composite connection can transmit anyway (though it of course may be treated as 480i).

[Stufio]

I just thought of something else that you may be getting ahead of yourself on. Some newer tvs do NOT like 240p and will just say no signal if thats the case.

Its why i always like to test old systems on a CRT. it wont tell you that you have no signal unless theres no sync. on a crt you can usually tell if a console is half way working because most of the time you will still get something on screen. whereas on a flatscreen if its not working somewhat it will always say no signal.

it also means there may be nothing wrong with your snes, just like the seller said.

That is an interesting thought. I don't think it is the case here though, as the TV recognizes my NES, Genesis, and N64 correctly. I feel like I've tested every testable variable except a new power supply, which I have yet to purchase.

Is your NES, Genesis, or N64 connected through component video? I'm guessing not.

EDIT: To clarify, HDTVs sometimes don't accept 240p through the component connector. ALL will support 240p through a composite connection since 15kHz is the max res that a composite connection can transmit anyway (though it of course may be treated as 480i).

All of them have been connected to the TV with Composite and they all worked. I now have them plugged into the video processor with S-Video and Component, and they both work correctly through the video processor as well (although they are read as 480i, they still produce a picture). That being the case, I have to assume it's something wrong with the console itself, and the fact that both consoles are having the same problem leads me to think it's something other than the console itself. While it is totally possible that both consoles are having the exact same hardware issue, I think it is much more probable that the issue is something that they share in common (power supply, controllers, etc.).

[tacoboy42]

dumb question but are you trying to power it on without a game in? also have you tried to power it on without a controller to rule that out? If both of those aren't working I would pick up another official power adapter from ebay.

[Stufio]

dumb question but are you trying to power it on without a game in? also have you tried to power it on without a controller to rule that out? If both of those aren't working I would pick up another official power adapter from ebay.

Those aren't dumb questions at all. Anything to help narrow down the issue. I have been booting it with games inserted. I have tried with and without controllers as well. Can controllers affect spmething like video output? I guess I assumed they were just a 'passive' part of the system.

[tjstogy]

Super nintendos are so cheap... I'd get one on eBay... and if you have personal attachments to your snes you can just "gut" it and swap the insides, leaving you with your original shell. Then sell the other one as non working

[Stufio]

Super nintendos are so cheap... I'd get one on eBay... and if you have personal attachments to your snes you can just "gut" it and swap the insides, leaving you with your original shell. Then sell the other one as non working

Thank you for contributing. If you had read my post, however, I did exactly that. I bought a second SNES because my original SNES was having problems. The new SNES had the same problems, which is why I made this post in the first place. Not trying to be a dick, but buying a third SNES is not my preferred choice, which is why I'm trying to fix the two non-functional SNESs.

[Zeromemory]

Have you tried to extract the composite video signal directly from the video chip? I know it's possible to do that kind of check on the standard NES system.

[Stufio]

Have you tried to extract the composite video signal directly from the video chip? I know it's possible to do that kind of check on the standard NES system.

No I have not. I have no idea how I would go about doing that...

[mvsfan]

https://console5.com/wiki/BA6592F

This would be the video encoder in the SNES. You would need to connect an rca jack to composite output.

I believe that the pin marked VO is composite output, but im not 100% sure. Could someone else Verify that?
Ive never been concerned with getting composite on an snes before, but i can see why you might want to do it to test.

I do just that on the turbografx a lot. The RF boxes in them go bad a lot and the quickest way to see if you have an otherwise working system is to bypass it.

[Stufio]

https://console5.com/wiki/BA6592F

This would be the video encoder in the SNES. You would need to connect an rca jack to composite output.

I believe that the pin marked VO is composite output, but im not 100% sure. Could someone else Verify that?
Ive never been concerned with getting composite on an snes before, but i can see why you might want to do it to test.

I do just that on the turbografx a lot. The RF boxes in them go bad a lot and the quickest way to see if you have an otherwise working system is to bypass it.

Hmm, do you literally mean to take a composite cable and attach it somehow to that pin on the board? Obviously I'd rather not solder it if it were just being done for testing purposes.

[Zeromemory]

From my understanding VO should be video output, just avoid VCC pin and you should be fine.

And you don't need to solder anything, just get a single RCA cable, 2 cables with aligator clips and some male jumper wires. If not, grab some sewing needle and hold it with the aligator clip on the side with where you will touch the pin on the chip.

On the RCA cable side, outer ring is GND, so grab it with aligator clip and the other end attach somewhere on the GND on SNES (shielding or somewhere on the board).
The middle part of RCA cable is the one which should be touching the pin on the chip. Since is too big to safely touch the pin itself, you should improvise as described above.

[ZellSF]

If audio isn't working (he said it wasn't) it seems pointless to troubleshoot this is a video issue no? The issue is that the SNES isn't working at all.

There's just two things he hasn't eliminated as a potential problem source: controller and PSU. He should eliminate both.

[Stufio]

If audio isn't working (he said it wasn't) it seems pointless to troubleshoot this is a video issue no? The issue is that the SNES isn't working at all.

There's just two things he hasn't eliminated as a potential problem source: controller and PSU. He should eliminate both.

I'm planning on visiting a flea market today that has a retro gaming booth to see if they have equipment to test the SNES. I would go to a gaming store, but don't have one near where I live.

[Stufio]

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