Any TV repair advice?? please!

justonemore_2

Have a CRT tv which needs to be 'hit' to get it to stay on... but only for the first 2 min of use??
Switching the tv on first use, shows black screen, and the tv switches itself off after about 5 seconds.
If you keep turning it back on the picture might have shrunk horizontally and when you 'hit' the tv the picture stretches then shrinks...any ideas?
also, after cycling through the above procedure a few times, it stays on fine for an entire evening.
Just wanting to avoid buying an lcd/led, any help thanks very much

fwor

I once owned a Philips CRT TV that did something similar. On close inspection, the high voltage transformer's connections to the PCB had developed dry joints, and would make reliable contact with the PCB only when warm.

Unfortunately it's not something to play with as a DIY job, as the high voltage side of a CRT TV can be very dangerous (i.e. potentially lethal) if you don't know what you are doing.

Richie-from-the-Boro

Go on to ebay, search for ~ CRT TV ~
then click on the ~ sort by postcode ~

I've just looked for you you can have a perfectly working one for 99p

In some cases you can have three of them for 99p

If I had three .. .. .. I'd have to pay you to take them away. I'm not being rude, they are or free, far too expensive to dispose of, have a look on ebay !

pompeyfaith

Why do you not want an lcd ? just curious

Rossy.

pompeyfaith wrote: »

Why do you not want an lcd ? just curious

My thought's exactly

LCD tv's look nicer, and produce a lovely picture when HD content is being viewed

birkee

Same old, same old!

Poor quality solder joints on components subjected to heat. (They degrade over time)
This, more often than not, is the high voltage transformer connections. The HV module can be easily identified by the THICK cable going from the transformer to the tube.
It's not necessarily the thick cable per se, but in the transformer module, there is a very high wattage resister which often gets degraded connections. It's usually green, but not necessarily so, and looks like a stick of rock with a wire at each end, and it's usually mounted on a heatsink. You need a soldering iron to renew the connections. (Remove old solder, and replace with new solder.)

THIS SECTION PRODUCES AROUND 20 THOUSAND VOLTS's, SO THE SET SHOULD BE TURNED OFF, AND LEFT STANDING AWHILE BEFORE LOOKING AT IT !!! (Allows time for capacitors to discharge.

Inner_Zone

Usually some free CRT TV's of all sizes on Freecycle / Freeagle. It not economic to repair them nowadays.

Ex brown goods engineer.

OK_Sauce

Not particularly wanting to answer for the OP but he may not want an LCD for a variety of reasons.

1) He perhaps wanted a simple solution to the CRT fault, hence a repair is cheaper than a new tv.

2) He may not have an HD source and therefore a CRT will provide a superior picture every time.

3) His TV might be in the corner of a room, therefore losing the advantage of a thinner tv.

4) He may have realised (as I have) that unless you buy a very good make model LCD TV (ie avoiding obscure/supermarket brands) that the picture on the LCD will be utterly s**t!

5) Oh and don't get me started on the sound quality......

victor2

Go and pick one up from your local tip (sorry - recycling centre). That's where my perfectly serviceable CRT TVs have ended up, they have a special area for them. Couldn't give them away!

maryke

If it only happens during the first 2 minutes then that probably means it has something to do with contacts/components that are only functioning normally when warm - like some people stated here, oxidized soldering joints could be one problem.

Eventually you would have to take it to repair since these soldering joints will continue to oxidize until they barely conduct. Your banging on the TV isn't doing any good to the other parts as well.

I wouldn't try fixing it myself if I were you, but if you find an honest place to fix it it should be fairly cheap (In case we're talking about bad contacts).

djohn2002uk

birkee wrote: »

THIS SECTION PRODUCES AROUND 20 THOUSAND VOLTS's, SO THE SET SHOULD BE TURNED OFF, AND LEFT STANDING AWHILE BEFORE LOOKING AT IT !!! (Allows time for capacitors to discharge.

AWHILE could mean WEEKS. The CRT acts as a very large capacitor and can take several weeks to discharge unless done safely via a long insulated screwdriver and a large value resistor.