NES no audio/video

[alf717]

I have an NES that I'd like to try and repair if possible. This is my tried and true NES since I was a kid. About a year ago I bought a new 72-pin cartridge connector. Everything thing was working fine and then I was met with a loud buzzing sound with no audio or video when I turned it on. The cartridges weren't staying down so I had to go in and tinker with it bit. When I opened the console up a second time I was removing a screw (circled in red) and my screwdriver got stuck to the side of the metal. It was brief but I felt a tug on the screwdriver. I immediately removed the screw driver but since then I've had the buzzing sound issue and no video. Since I've gotten a bit better with repairing older consoles I wanted to take the time and see if I could bring this wonderful relic back to life.

http://imageshack.us/f/835/76386932.jpg/

http://imageshack.us/f/109/83159950.jpg/

Cliffs:

1. Went in to replace the 72 pin connector.
2. Screw driver briefly got caught on to the metal piece circled in image #1.
3. No more audio/video
4. Buzzing has been significantly reduced but still no video/audio.

[MottZilla]

Turn the system on without the cover on it and leave it on for a few minutes and observe for any intense heat or smell like burning/melting plastic.

The area circled is where the voltage regulator goes. I'm hoping you didn't stick the screw driver in there with the system plugged in. It's possible you damaged the regulator and it could just be replaced and fixed or it's also possible you created a short that fried either the PPU or CPU chips. That's what the "smell" test is about.

I have a NES that doesn't work even after replacing the 72 pin connector. You can tell the PPU is functioning as the picture is stable and working but nothing ever happens and you can smell the plastic melty smell and feel more heat than usual I believe as the CPU bit the dust.

[alf717]

Is five minutes a good test for this? I didn't want to risk over heating anything. The console was off and not plugged when I work on it. Still I did not hold the power button in to make sure no power was still in the unit. If I were to replace the regulator where would be a good place to find one?

http://imageshack.us/f/40/hotyk.jpg/

In that image I circled what I felt was really hot. The chip further to the left was hot to the touch (took a few second to feel the heat). The chip in the middle was hot. It hurt my finger about a one to two second after placing it on that chip. The other section was somewhat warm as well but not as hot as the two chips on the board. Again I only tested this for five minutes but didn't smell the usually smell I'm used to when electronic equipment is burning.

[Calpis]

Hot to the touch isn't good. Maybe you shorted the unregulated AC to a power rail.

[alf717]

Hot to the touch isn't good. Maybe you shorted the unregulated AC to a power rail.

Yes but is it fixable? :thumbsup: I'll change out whatever I need to change I just want to know if I can save this NES.

[APE]

Yes but is it fixable? :thumbsup: I'll change out whatever I need to change I just want to know if I can save this NES.

Maybe. Maybe not.

I made the mistake once of not reading the NES' power brick carefully and plugged it into a SegaCD. Piped 9vac into a console expecting 9vdc and promptly blew the fuse. Put another in, blew it.

Being a bit too smart for my own good and thinking the brick was just fine I shorted the fuse points with wire. You can guess the rest.

If you're lucky the NES hasn't been fried. The fact it heated up is very, very, very bad.

[takeshi385]

while you have the nes open try to disable the 10 nes chip , that may solve some problem down the road.

[Alchy]

I made the mistake once of not reading the NES' power brick carefully and plugged it into a SegaCD. Piped 9vac into a console expecting 9vdc and promptly blew the fuse. Put another in, blew it.

Being a bit too smart for my own good and thinking the brick was just fine I shorted the fuse points with wire. You can guess the rest.

My mate fried his Mega CD recently, with a NES PSU same as you. Makes you wonder how many Sega consoles that damn AC NES brick has killed over the years.

[takeshi385]

maybe you could look into getting another nes , i realize that you have fond memories with this nes, though fixing it may cost you more than it worth. if you want you could take out the new nes and put it into that nes shell.

[alf717]

Well if you guys can help me with what you suspect should be swapped (at this point I assuming just the regulator) then I will try that. What are my odds of finding said parts? Am I going to need another NES or can these part be found online? Perhaps it would be easy to just replace the NES but since this has sentimental value I'm running and gunning to fix it first then replace as a last resort.

maybe you could look into getting another nes i , realize that you have fone memorys with this nes, though fixing it may cost you more than it worth. if you want you could take out the new nes and put it into that nes shell.

Part of the problem is finding an NES at a reasonable price. The other option was a 3rd party unit but I don't know of any that are any good. I figure if the NEs is gone then its gone but I want to try and fix it since it is a paper weight in it current state anyway.

[MottZilla]

It sounds like the CPU is fried if it gets hot to the touch. The plastic melty smell would probably be caused by it warming the case plastic, if it was out of the case you wouldn't smell that.

If the PPU is warm but not hot, you might see a stable but blank picture on the TV. My fried NES is like that. The problem is that this means you probably need a new 2A03 processor. These are custom made for the NES/Famicom. Maybe you can find a broken NES that still has a good processor in it and you could desolder it and put it into your board. But it's possible when you shorted something that more parts may be damaged.

The regulator is probably fine and you could test it with electrical test equipment to see if the NES board is getting +5V DC from it. It sounds really like your screw driver discharged current when it shorted between two points and fried certain chip(s).

The NES I have with a bad CPU is just going to sit around until I either throw it away or somehow end up with a 2A03 chip that's good to try putting in to see if it works again.

[takeshi385]

i see what you mean alf717 , saving money isn't everything its the sentimental value , like with photos of my childhood.

[alf717]

Alright I'll keep my eyes peeled for a new NES but I'm going to hold onto this one just in case. I was planning to do a new WTB thread anyway for parts and etc. So I'll try my luck there as well. I'm not going to let this one go just yet though. :-) I have a feeling I'll come around to fix it somehow.

[RedROCKET85]

I hope this isn't toooo far off topic, but just for the sake of weighing in, I'd like to add that I think it's wonderful that with so many cheap alternatives (NES on a chip clone systems, EMU, etc) people are still willing to fix up and refurbish their old NES consoles. My Mother in law mentioned recently that she had a broken NES in the closet, and wanting to do a good deed, I thought at first about purchasing a NEO-DUO, or equivalent, but then the obvious struck me. That's not a NES, and their are plenty of vendors still servicing the system. This whole thing just makes me happy. Good job everyone.