phd@SPEECH1.CS.CMU.EDU (Paul Dietz) (11/09/87)
I have a vintage 1981 Quasar color TV which died on me recently. Here are the symptoms: Picture goes totally black, sound goes away, however there is a high (15kHz?) pitch hum. At first, a slight tap on the set would get it working again. But now, I have to bang it hard for 20 minutes before it starts up (which is clearly beginning to annoy my neighboors). Any suggestions from out there in net.land? I've heard rumor that it's usually the flyback transform that dies, but I haven't got much experience in this area... As always, any advice is much appreciated!
bobc@hplsla.HP.COM (Bob Cutler) (11/11/87)
Since you can get the set working by hitting it, I would suspect either a bad fuse, or cracked solder joint. Check the continuity on all internal fuses (if there are any). You'll have to test them since they won't look blown. Cracked solder joints can be a pain to find. Start looking around connector pins that are soldered through the PC board. These solder joints take a lot of stress. The crack is real hard to see (It looks like a circle and runs around the pin). Sometimes the easiest way to find a cracked solder joint is to apply power and use a NON-CONDUCTIVE tool to wiggle wires, connectors, and components. If you do that, PLEASE DON'T ELECTROCUTE YOURSELF. Remember that there are lots of lethal current sources inside of a TV.