I have two systems (out of 8 others that work perfectly), that both have the exact same problem after applying basic fixes to all of them (basic being: rebent pins, cut lockout chip, and general cleaning)

Both of the systems will power on, but then no signal whatsoever is sent through either the a/v cables or r/f switch no matter which is hooked up. It's not that it's just not working, but I can tell there is no signal whatsoever coming from the video/audio because my television displays a blue background if nothing at all is being sent to it.

 I have only had something like this happen one time before, and then it was only the audio that was completely broken and not the video as well (would also be nice to know that problems fix ).... so has anyone seen this happen before or know what the problem could be or a possible fix? I don' really have access to soldering equipment and a voltmeter so I can't really do any serious repairs, but just even knowing what the problem could possibly be would be a better place than I am at now with this

Thanks very much