Two days ago I got a sony slv-676uc player at the goodwill for a few bucks it worked great that day but when ever I tapped on the top of the case or anything it would cause the video to futz out for a second. Today I cracked it open to clean the heads and when I put it back together nothing on the screen of my '83 zenith through the rf imput so I got another set that rca imputs and it works fine like that butr not through rf? After this I opened up the whole thing (really neat design sony but seems failureprone if used alot)
and cleaned the contacts where the boards connect still the exact thing!!!
Normaly I would just forget about it but on the tv I want to use it with there are no other imputs besides the normal rf...
anyone have any ideas before I go and resolder that whole section?

Just shooting in the dark here, but maybe a previous owner overtightened the RF connector and twisted it, breaking the center wire off of the PC board. It used to drive me nuts; I'd see people horse those F-connectors down with the biggest wrench they could get on it.

Could be a cold solder joint where the RF module connects to the mainboard too.