I have an RCA XL-100 CTC185 table model (19") that fell off its stand last year. The set worked afterward, but I noticed color splotches all over the picture. I tolerated the problem for a few hours, then decided to at least try to fix it. Had an old PM speaker laying around, so I brought it out and pressed the magnet against the CRT screen. A couple of sweeps across the screen and the splotches disappeared. The only thing I can figure is that when the set fell (face down), the shadow mask got bent, and the magnet treatment reshaped it. I don't know if this will work again (the TV is ten years old), but the magnet did get rid of the color distortions this time around.
I'm amazed the automatic degausser didn't eliminate the splotches the first time I turned on the set after it fell. It was suggested to me in this forum that perhaps the degausser was not operating; if it were, it would have eliminated the splotches the next time the set was powered on. I'm not sure myself if the degausser works or not, although I do hear two clicks each time I power on the set. The TV works perfectly from then on.
Hmmm. Now I'm wondering. Why am I hearing two clicks when I turn the TV on? I'm sure the first is the relay for the auto-degausser, but the second one has me baffled. As I said, the set works exceptionally well once turned on, so I don't think there are any problems with the power supply or anything else associated with it; the only thing I can come up with is that the first click is the relay closing, while the second one is the same relay opening. Or is there a start-up relay in the set's power supply that opens and closes along with the degausser's?
Thanks in advance for any advice on this. I hadn't been thinking much about the cause of these relay clicks until I started writing this post. Why would a modern TV power supply even need a start-up relay in the first place? After all, there was never any need for relays in tube-powered sets, except in remote-control models in which a relay was used for AC power switching. The automatic degaussing circuits in older sets, moreover, did not use a relay, but a thermistor. I wonder why the design of today's TVs seemingly has reverted to mechanical relays to activate and deactivate the degausser, when thermistors did the job exceedingly well for decades in older sets?