The thin TV line
October 25, 2006 7:16 PM   Subscribe

Is my TV dead?

My (roughly) 15 year old TV (a Mitsubishi) starting acting weird a few weeks ago : no more vertical scan, so that the whole image is "scrunched" into a thin horizontal line in the middle of the screen. A tap on the side would restore the picture, but that doesn't work anymore. It worked ok for a few minutes tonight, but simply changing the channel brought the problem back. Any hope? Or should I be looking for a new TV?
posted by bluefrog to Technology (16 answers total)
One of the electromagnet thingies that make the stream of electrons move up and down the screen is kaput. Your TV is dead, as I can't imagine repairing that would cost much less than buying a new TV. I may be wrong.
posted by Jimbob at 7:22 PM on October 25, 2006

I was going to comment that most electronic problems can be traced back to a single component that's bad, but the big expense is labor... And DIY TV repair is probably about as safe as TV heart surgery.

TV's come a long way in 15 years. If you're really determined you can try to get an estimate to fix it, but just on account of it being 15 years old and starting to be on the fritz, I'd start shopping.
posted by fogster at 7:31 PM on October 25, 2006

What they said. It's a single part, which if it was cost-effective and the parts were available would be an easy fix, but it won't be cost-effective. Get a new tv.
posted by raf at 7:50 PM on October 25, 2006

For future reference, if tapping fixes the fault then it's likely a mechanical problem - dry (unsoldered) or cold (fractured) joint, broken wire, faulty plug/socket, etc.

This is the time to get it fixed! At this stage it's likely to be relatively easy (& cheap) to track down with some judicious tapping; leave it until it fails totally and it's a often much harder (& more expensive) job.

Having said that : a 15 year old TV with a vertical deflection fault? Dump it...
posted by Pinback at 7:53 PM on October 25, 2006

Plasmas and even 1080p LCDs are below $2,000 these days, which is really cheap in thin TV terms. You can buy an amazing TV for about $1500 if you shop around a bit.

And I know that might sound high, but trust me -- after you watch your first DVD at home on a 42" landscaped screen (pick a movie you're familiar with), you'll wonder why you didn't do it years ago. I cut my movie going way, way back after I got one and now instead I just rent DVDs six months after a movie comes out in the theater and enjoy it at home instead (and it's much cheaper, to boot).
posted by mathowie at 8:11 PM on October 25, 2006

I recently bought a Philips 42" plasma (720p) from Philips' Web outlet store for $999 (plus shipping and sales tax, which added another $200-ish for me). It is a far, far better television than the flat 27" standard-def JVC CRT it replaced, which was only 5 years old and still worked fine. IIRC I paid over $750 for the JVC in 2000.

Philips is replacing the tube in my new TV, as it arrived with a fault (a bright stripe of white static on the right edge) but it has an in-home warranty, so they're sending someone out to get it. It probably get damaged in shipping. For the price, I'll tolerate a little downtime.

Even with the fault, though, the picture's great. The linedoubler and scaler in this TV are really very good. Even blowing up letterboxed standard-def to fill the screen (e.g. Battlestar Galactica), which should look awful, looks decent -- a little soft, but still way, way better than the JVC. DVDs look phenomenal, as do Divx AVIs of downsampled HD broadcasts played on my EyeHome network player (e.g. Torchwood, which I'm only downloading because it's not airing in the US). I haven't even looked at HD on this set yet and I'm finding it well worth the money.

This deal was due to expire tomorrow, but as Philips' outlet Web site is undergoing some maintenance, they will be extending the deal until November 2. (They will probably run it again if you miss it.)

TVs have become amazingly better in the last 5 years, let alone the last 15. I thought I'd be waiting another two or three years before I went HD, but even if you only have standard-def signals, you will probably benefit from an HD set in the 37" or 42" size. (Any bigger than that and you will probably want actual HD broadcasts, depending on your viewing distance.)
posted by kindall at 8:26 PM on October 25, 2006

One of the electromagnet thingies that make the stream of electrons move up and down the screen is kaput.

Yeah. It's called the flyback transformer.

It's not dead, though. Only sleeping. If you like waiting on hold for hours to get the part number, then mucking about with high voltage and soldering irons, you could probably replace it for twenty bucks.

Or you could go on your local craigslist and probably get a replacement television for free. Seriously. Everyone's throwing away their (perfectly good) CRT's for (perfectly crappy) flatscreens these days, so I'd bet dollars to donuts you could find a new (used) one someone's giving away.
posted by Civil_Disobedient at 9:15 PM on October 25, 2006

It isn't necessarily the transformer; a goodly number of problems with CRT TVs originate with dying electrolytic capacitors, in this case in the circuit that generates the vertical scan. The scan generator itself often lives in an IC that can also get fried. Either way, it should be repairable for a part that costs between 5p and £10 plus an hour (max) labour. (That said, if you have to ask about TV tubes you're really not qualified to go poking about in them without doing some proper research on the very real dangers, which can kill you in unexpected ways.)

But, if you're curious, the Sci.Electronics.Repair FAQ has various handy hints and explanations, specifcally. And you could have a look on sites like this for specific tips.

Apropos of such things, I have a friend who, whilst doing a PhD in Electronic engineering, made beer money by generously taking people's "dead" TVs (of the big and expensive variety) off their hands, replacing the 10p component / dry joint, and selling them on at substantial profit.
posted by Luddite at 3:17 AM on October 26, 2006

It isn't the flyback transformer... that's part of the horizontal sweep section/ high voltage generation block.

This TV has full horizontal deflection and video... that means the high voltage (including the flyback) and horizontal sweep are intact. This is a vertical problem. That block consists of a vertical oscillator, output section, and portions of the deflection yoke.

It sounds like a loose connection internally.

The fact that a thump restores it suggests this. Most problems in most electronics are connector related.

Candidates are the connections to the deflection yoke, and in a 15 year old set, perhaps some socketed ICs and/or transistor.... maybe a cold solder joint.

I'd unplug it, take the back off, avoid the BIG RED WIRE going into the side of the CRT... and disconnect/reconnect the connectors going to the big coils of wire at the extreme back of the CRT. Do this with as many as you can see, but do make sure the set is unplugged.

Reassemble.... re-assess. You'll know quickly if it had a lasting effect.

THe other possibility... cold solder joint.... would be harder to fix but have the same symptoms... vibration sensitivity and intermittent operation. THat's service tech territory.

Worth a try, IMO. Good luck.
posted by FauxScot at 4:40 AM on October 26, 2006

you can buy a nice standard-definition tv for a lot less than the $1500-2000 prices people are quoting for enormous HD screens here. I'd be surprised if you couldn't find a 27" TV brand new for under $300 - or used off craigslist for less than half of that.
posted by chrisege at 6:14 AM on October 26, 2006

Listen to FauxScot.
posted by flabdablet at 6:31 AM on October 26, 2006

I had an old Zenith set that had this exact problem (incidentally, it went out right before 9/11 and I didn't see actual footage of the planes crashing into the towers until December).

Anyways, if you're not inclined towards electronics repair, I hauled my TV down to a repair guy around the corner. It cost $60 (including parts and labor) and about a day to fix. This was in West Philly.
posted by Mercaptan at 6:43 AM on October 26, 2006

I had my 12-year-old Magnavox fixed last year, at the neighborhood TV repair place. It cost $110 to replace a bad capacitor. Works fine now. Find your local TV repair place. they'll tell you it will cost some minimum amount to diagnose the problem, and then they'll do the diagnosis and give you a repair estimate. In my case, they applied the minimum charge to the repair.

I'm assuming that because you asked if the TV is dead (and implicitly asked whether it could be fixed), you're not in a hurry to spend $1500 to have the wonderfulness of widescreen.
posted by Kirth Gerson at 6:49 AM on October 26, 2006

I had my 12-year-old Magnavox fixed last year, at the neighborhood TV repair place. It cost $110 to replace a bad capacitor.

If you're going to take it in for repair, bear in mind that the Philips Web Outlet (which I recently plugged) had refurbed flat-front 27-inchers for $200 last I looked. Your 15-year-old TV is not flat-front, I bet, so even that could be a substantial upgrade.
posted by kindall at 8:03 AM on October 26, 2006

Our spare-room TV, an ancient Curtis Mathes, does that. The picture is fine if you set the TV down centered on top of a 1.5" thick dry sponge (the TV itself probably has 1/4" feet on the corners, so the middle underside of the TV would normally not be pressing against anything). There are probably other household items that would press on the right magic spot, but the sponge was an accident and it worked and it keeps working.

It's probably worth a shot, if you're having trouble finding a repair shop. Sponges are cheap.
posted by Lyn Never at 8:22 AM on October 26, 2006

Regarding listening to Fauxscot, avoid not only the BIG RED WIRE, but also the legs of any large capacitors. The shock from one of these probably won't kill you, but it can make your muscles spasm - if you're unlucky that can take your hand into the BIG RED WIRE (of death) or give you a nasty cut if your hand catches something sharp.
posted by Luddite at 9:07 AM on October 26, 2006

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