PCA Forums

Not exactly a computer hardware problem
I have a Sony Trinitron TV that is around 6 years old. It is a 27" top of the line when I purchased it.
Well now it will not stay powered on. In the middle of watching TV the screen will turn solid green the quickly power off. I can get the TV to come back on but after a couple of seconds to a couple of minutes it will do it again. I hate to think that it is hosed....a $900 sony tv should last longer then 6 years.
I just moved into a new home....so the wireing is brand new and none of the other equiptment on the breaker is having problems.
anyone heard of such a thing?

"Shot in the dark"
Thanks

My guess is that some components just aged over the years and became more susceptible to heat. At least that's what I think looking at your problem description.
Maybe it's a bad soldering point, maybe an old capacitor, tough to say.

Bring it to a TV repair shop, explain the problem and ask them for an estimate on the repair.
Trying to find the bad piece by yourself isn't impossible but requires the original circuit diagram (which includes test points and expected voltages), a good measuring instrument and some experience in doing this.
That's why it's better to bring it to a TV repair shop, they have the equipment and the experience

Actually, I have heard that Sony TV's break more than any other brand. Now, that could be it only seems that way because they are popular and generally higly regarded, but I have heard it said by a few people.

If the picture still looks good, then it is probably something minor (like Doc said). Take it in to a shop, and you can probably get it repaired for <$100. I know it sucks, but it is better than buying a new set.

Oh, and PLEASE don't try to fix it yourself. Unless you really know your poop on TV repair, you can shock the bejesus out of yourself.

you can shock the bejesus out of yourself.

so true, don't yer ever try to touch parts of a running TV which are considered HIGH VOLTAGE, leaves at least a small burning wound on the tip of your finger (especially on a RUNNING tv set ... I should know)

Actually it's VERY dangerous to even mess around inside a TV set with it unplugged if you don't know what you're doing.

The high voltage section maintains a charge after turning off the TV, and will retain that charge for several hours and even days.

Touching the high voltage anode on a TV, even one that's unplugged and turned off is not a good thing.

I've fixed a few TV's before... I've been lit up like a Xmas tree from hell! Didn't feel real good let me tell ya... But dammit i got it fixed.... My parents have an RCA that was doing a similar thing... It would turn into a green line then turn off... I cracked open the back and started poking around and found a little PCB on the back of the CRT that had a bad solder spot... After gettin' the old solder off and puttin' some new on its worked flawlessly for the last 4 years....

I may be wrong, but I think the tubes essentially act like a giant cap. So you end up with a large R and C in a big RC network. Hence a very long discharge time for the tube. If you do decide to muck around inside the TV, be extra careful. Unplug it and let it be for at least a day, maybe 2-3. After that, everything should be discharged thoroughly.

I still recommend that you do not try it yourself, though.

Yes it's the combination of the tube and flyback creating a circuit that holds a charge.

WARNING! THIS CAN BE DANGEROUS! I can in no way be held responsible for any injury! Do this at your own risk!

The way TV techs do it (I used to service TV's but I don't like it) is to connect a jumper wire from the TV chassis (common ground) to the metal of a flat screw driver to ground it. Then slip the screwdriver blade under the high voltage anode cap (the big rubber cap on the side of the picture tube with the heavily insulated wire going to it).

WARNING - THE TV SHOULD BE TURNED OFF AND UNPLUGGED FROM THE WALL BEFORE DOING THIS!

If there's a charge in the circuit then you'll hear and probably see a notceable arc of electricity as the charge is dischaged through the screw driver to ground (WARNING: ONLY TOUCH THE PLASTIC HANDLE OF THE SCREW DRIVER WHILE DOING THIS OR YOU'LL GET ZAPPED - SCREW DRIVERS WITH A RUBBER SLEEVE OVER THE PLASTIC HANDLE ARE SAFER SINCE HIGH VOLTAGE CAN JUMP ACROSS PLASTIC! ALSO NEVER TOUCH GROUND YOURSELF WHEN YOU DO THIS!).

After that the set is essentially safe to work on until you power it up again.

I don't like messing around inside anything bigger than a 20" TV because the voltage, even just the charge stored in the tube, is quite lethal and I've been severely electrocuted myself (not by a TV - 1000 volt power supply in an old ham radio rig).

I will open up smaller sets and computer monitors if it's something simple. Most often older computer monitors with soft or dim pictures can be milked for some more life by adjusting the focus and the screen voltage (WARNING: This has to be done with the monitor turned on and with insulated tools - it's very dangerous for the untrained!).


Unless you feel frisky, it's best to take TVs or computer monitors to mom & pop TV shops and let them work on it. Most will give you an estimate for a reasonable price or even free.

Uh, FP's method is usually ok, but I have seen electrolytic capacitors explode before.

Once again, I urge you to use caution or not do it at all.