I've fixed up lots of NES systems, so I'm well aware of the 72 pin problem, but I have 3 NES systems that are doing really wierd things, and I don't know where to begin. I would really appreciate any advice on how to fix them. Here is a description of each one.
Problem Child NES #1: Picture comes up with a nice 72 pin but the title screen for Super Mario has numbers in it.
Problem Child NES #2: Picture comes up with a nice 72 pin using the RF switch, but you have to wiggle the RF switch to get a picture. If the RF switch isn't in the perfect spot, all you get is snow. If I connect it to a TV using AV cables, all I get is a black screen.
Problem Child NES #3: I get sound with a nice 72 pin and AV cables, but no picture, only a black screen. Connected with a RF switch all I get is a black screen and no sound.
Thanks in advance for any help.