TV repairable?

See if the problem can be influenced by vibration. Smack the set on it's side to see if you can influence it. If so turn the lights out and look inside the vents. See if you can see small sparks that could be a bad solder joint. Because the problem comes and goes it may very well be a bad solder joint or connection. Be safe. If you don't know of the dangers involved then stay away from the repair.

Bowing in of the sides of the picture has nothing to do with the crt , it is the deflection yoke (coils) at the base of the tube that move the beam from one side to the other and top to bottom. Have you tried running the set with the back loose enough to greatly lower the internal temperature, and see what effect that has.

The real answer, sadly (it offends me to say this) that it's likely not

nate

Since a little after vacuum tubes went out, there's not much you can do unless you have some electronics skills or want to learn them. Back in 1980 a buddy gave me my first color TV, but it had no color. There was a repair shop and I took it there after the mechanical tuner screwed up. That guy fixed the tuner and replaced the "color chip" for $75. Good deal, since a TV like that was about $300. Now you can a much better CRT TV for $50-100 at a thrift shop. I've got a perfectly working 27" Magnavox in one room my wife paid $30 bucks for, and a 30" Bell-Howell in another room that my son picked up for $100 at a place called Cash Converters around here. Not a pawn shop, but you they'll pay for used working electronics and other crap. Add $10 for a universal remote and you're set. I've got perfectly good 18" and 21" CRT monitors that I paid good money for sitting idle because I got flat screen replacements as gifts. Kinda pissed me off but I couldn't say anything. Wouldn't look right. Waste of money to me. Probably be a waste of money for you to get that fixed. I've got a 27" CRT TV in my bedroom that I was sure needed replacement about a year ago when it would go blank. Smacked it a few times and it hasn't acted up in months.

--Vic

Yes, but don't give the impression that replacing the yoke will solve this, because he might go do it, even though yokes are expensive. I think it more likely it is the circuit that powers the yoke.

Maybe, but this is a "repair" group. Some of us live to repair.

STill, what I would do at my stage is nothing, and figure a few minutes of distorted picture is nothing, and I'd watch it the way it is until it got intolerably worse, or I got a free tv somewhere.

When I was eager to repair tvs, I might have tried looking for swollen nd broken capactitrs, or signs of burned parts, but otoh by 15 years ago, everything may have been in an integrated circuit.

OP, whatever you do rememeber that the picture tube holds thousands of volts, even after the set is turned off and unplugged. The picture tube is one big capacitor. I've always deeply avoided the thick red wire that goes to the picture tube, and I've always avoided the whole surface of the picture tube also. Especially if it is dust covered. Maybe dust conducts elecricity, for all I know. (It has 15 to 20 thousand volts when running, maybe more for a picture tube as big as yours.)

The yoke also has a couple thousand volts on some leads, but only when the tv is on IIUC. YOu can always use a voltmeter to check on that, but not so much the picture tube, whose voltage tends to be hidden under a big rubber wafer at one the picture tube end. There used to be a metal cage at the other end, for the tech's safety, but those went away 20 or 30? years ago to save weight. It's also hard without a lot of experience, more than I have, to fix these things without a schematic, and they are about 30 dollars last I looked, years ago.

It stinks, doesn't it?

If you can find the problem and repair it yourself, it may be worth it. If you have to pay for repair, it is not worth investing much in a 15 year old set. There are some amazing prices on 42" sets now and the picture quality for HD is a huge step up.

When my old CRT got fried after a power surge, I was happy to buy a new set. After 6 months, I'm still amazed at the picture quality with HD.

besides a brand new LCD tv of the same size will save lots of electric. the savings on your electric bill might just pay for the replacement over a few years.

I'll bet it is a bad capacitor, fixed hundreds of video game monitors with similar symptoms. Most of the time we don't even test the caps, look for parts of the circuit board that look like they run hot, then replace all caps in that area. Also replace all caps rated for 100 volts or higher, they go bad much more often. Also if you know your way around a monitor, be sure to change the caps in the vertical and horizontal circuitry. For newbies in the video game monitor repairs, lot's of people put together a list of all the common caps that fail on that particular model and sell you a bag of caps and a picture showing what goes where. The "cap kits" will fix several problems at once, including problems you didn't notice yet but are about to go.

Actually my TV is doing the same as yours but it stays that way. When it quits I'll probably take a look inside, but chances are I'll toss it and get a new one instead of fixing mine. TV's have a lot more components than cheap video game monitors and aren't as easy to fix (not for me anyway).

OH, no way is that a sign of a bad CRT, and no way is the yoke itself bad, just the circuitry that powers the yoke.

I'm with you. Santa got me a 37" LED/LCD and it didn't cost much more than $500. Wattage on the 27" old tv, 180 Watts; new tv,

If only I could remember the HD channel numbers that carry my usual channels. Getting there.

nancy

This looks like a problem with the automatic degaussing circuit. Electromagnets are energized when power is first applied to remove any stray magnetic fields from the CRT. The degausser should be deactivated by the time the CRT warms up. Usually a thermistor (a fairly inexpensive component) is the culprit. If you have service information (e.g. a schematic) you may be able to fix it inexpensively.

But, as others have pointed out, it's not economically practical to put much effort into repairing such a technologically obsolete device.

Check the model and chassis number online, there are a number of databases describing faults common with various models. Ask on sci.electronics.repair, they may have a general idea.

Jon

Probably a tube is getting weak. Remove the back, label all the tubes for location on the chassis, so you can put them back in the same socket. Pull out all tubes and take them to your local drugstore or hardware store and test them in their tube tester. Replace any bad ones and you should have a good working tv for several more years.

Jack

On Sun 16 Jan 2011 11:32:32p, told us...

I haven't seen a tube tester in a drugstore or hardware store in years, nor have I seen a television made in the last 15 years that had more than a picture tube. The remaining circuitry was solid state.

Hi, We are talking about tube set? Whoa! I have a tube tester real professional one. I use it very often working/repairing guitar amps.

On Sun 16 Jan 2011 11:57:13p, Tony Hwang told us...

symptom

I can't believe the OP has a tube set, and I don't recall it being said. Most sets made in the last 15 years were solid state except for the CRT.

You beat me to the bad capacitors. 15 years is a darn good life for consumer grade electrolytic capacitors. I had a customer who's Viewsonic LCD monitor on his server/office computer died after a year. I thought it a shame to toss a nice monitor so a little Google search turned up a common problem with an electrolytic in the power circuit on the main circuit board. The store had a problem with recurring power surges and even though there is good surge protection on the computer system, what can get past the surge arresters will damage some components. I believe it was a 100uf 16volt electrolytic and when looking at the circuit board I noticed lands on the board for a parallel capacitor. I installed two 47uf 35volt caps and there have been no more problems with the monitor.

TDD

? wrote

A flashback to 1963, brought to you by Jack. Thanks for the chuckle.

It's more like a problem with the 'pincushion' correction circuit (if the set has one). This allows you to set the edges of the picture so they are vertical (and horizontal), and not bowed inwards or outwards. The adjustment control could be a small preset potentiometer, which has a dirty (intermittent) contact. A quick twiddle might clear the problem.

However, the problem might be any of the components or soldered joints in that part of the circuit. I recall that, when it was 6 months old, my

But, as others have said, unless you're really into electronics, maybe it's time to treat yourself to a new, flat-screen set. If you spend some time carefully setting up the picture, you'll quickly become accustomed to the 'different' picture quality - and maybe eventually learn to like it!

The only tube he will find is the CRT (at that age TV). Another comment about degaussing, that is an AC coil that would cause it to be jittery not stable. I agree with a bad capacitor (electolytic).