Sony is driving me mad!!!

[josephdaniel]

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?