NES not working; Audio is fine, but no picture. Pin Connector is fine also. What do I look for inside unit?

Question

My NES powers up, does not blink, but when I power up, all I get is the audio, and a distorted video. I have experience replacing 72 pin connectors, so I know that is not the issue here. It is not the AV connector or the RF adapter, since both were tested on another NES, as well as the Power Adaptor, and all work fine. I've tested several games and pin connectors on this system and same problem occurs: powers up with audio but no picture. Having opened up the NES, I wouldn't know where to look for the problem. Is there something I could look for, a specific wire, anything. Would I need to open up the metallic power section in the upper right corner? Any suggestions? Please help! Thanks!

Answer 1

well, i've never had such a problem, and what i'm going to suggest, you've probably already done.

where the AV - video plug is, i'd follow that, and make sure everything looks unscathed/undamaged. then do the same with the RF entry point

sounds to me like some corrosion has possibly occurred overtime.
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also, see that the channel is on 3 or 4 (on the NES as well as the TV) - i've been embarassed before because the solution to the same problem for me was that i thought my tv was supposed to be on 4... and here the back of the nes was set to 3 somehow