Another TV issue

[Tom41]

As I mentioned in my previous thread, my TV has recently bitten the dust and won't power on (it only makes a loud buzzing noise). I have a spare TV which I'm using right now, but it has a couple of things wrong.

First, and most annoying, is that it makes a loud high-pitched noise when on. I don't mean the quiet whistle that most CRT TVs make when switched on, this sounds similar but is MUCH louder. Sometimes, if I hit the top of the TV, the noise will stop - only to come back a few minutes later.

The second thing is, the colors are much too bright - I have to turn the color control down to make them look right. If I touch the buttons on the front of the TV, the color level changes and occasionally goes back to the 'proper' level. I assume there might be a loose wire or dry solder joint on the board - what do you think?

It's a Sony Trinitron set, 14-inch screen, PAL (60hz compatible) with mono sound. A friend of mine (who is good with electronics) says that I should try reseating the suction cup on the tube to try and fix the whistling problem. But to do that, I'd probably need to discharge the tube. I read somewhere about wiring a screwdriver to ground and pushing it under the suction cup, but that sounds dangerous! How DO you go about discharging the tube and reseating the suction cup anyway?

[kc8adu]

Re: Another TV issue

try sticking a toothpick between the core and body of the flyback.
the core sometimes gets loose and sings to you.
dont need to mess with the hv lead.if it was loose/dirty it would hiss and arc loudly.

[chipper]

Re: Another TV issue

Loud whistling from CRT's comes from where the suction cup (red wire) lead begins usually. Then it is transferred to the suction cup and clip on the tube opening. Sometimes , all that has happened is that someone has turned up the flyback settings that are the 2or3 (black plastic cross shaped or star screws) that are on the side of the unit where the red wire leads to at the PCB. Alot of tv's have built in holes in the plastic cover that allow the RGB or RED,GREEN,BLUE setting screws to be altered according to preference , and a whistle may result . Each setting screw should be changed with a plastic screw driver (metal is OK) , until the whistling is gone or lowered. With older tv's once this happens there is usually no cure , but , if they were maladjusted by a user , they can be corrected through viewing the colors vs. the whistling sound.

You should turn the brightness up full (visable) at the tv before setting the flyback , then turn it down accordingly after you have achieved the best (less whistling) settings. This should get rid of the problem. If it doesn't the flyback transformer is worn out or almost ready to stop working (reached it's life's end). [too many hours on it]