I have a flat screen television that insist on making a loud buzzing noise whenever I turn it on. This television is no longer under warranty and I think it would cost about 200 bucks minimum to get it repaired. Which means that I’d rather spend 400 bucks on a new television then get it repaired. Of course I’d rather fix it myself then spend anything. I’m not all that good with electronics but I thought I’d give it a whirl.
Does anyone here have any experience fixing a television set? I went ahead and took the back cover of the television off and the buzzing is coming from whatever it is that is attached directly behind the vacuum tube. Any ideas?
That would be the flyback transformer. Don’t touch it; the voltage it creates can easily be LETHAL! My advice is either get the repair estimate to see if it’s worth fixing, or buy a new set.
I appreciate the tip QED. I figured I’d either have to suck up the repair price or just go ahead and get a new television. Is my television in any danger of simply dying any time soon?
I’ve got a related question. I’ve got a broken TV/VCR combo that I don’t want to fix. Where’s a good place to start looking for charities that accept broken electronics?
Unplug the set, put the cover pack on, plug it back in. And don’t ever run a TV with the cover off unless you are an expert. As already mentioned, there are a whole lot of dangerous voltages in a TV set. Even one that has been off for a long while can still have scary charges stores in capacitors.
I know of no fix for your set that a novice could do that wouldn’t be in danger of killing you.
“Where’s a good place to start looking for charities that accept broken electronics?”
People donate them to the three thrift shops I work for & say that they work great. ha… We take them but make a note on what happens when you use them.
What is the make & model & year of your tv MGibson? It’s posted on a paper label on the back of the tv set…
Why don’t you get a new one from circuit city circuitcity.com (i think they have free shipping on everything) ? $400 buys a lot of tv. I see a flat screen Apex 20" at Albertsons.
Though playing in the high voltage section is potentially dangerous, if you’ve got a basic background with electricity, it’s not tough to fix, and if you’re careful you’ll be fine. That is assuming it is the flyback that’s bad, which it almost certainly is. The buzzing you’re hearing by the way is in the metal plates that make up the flyback. They’re normally epoxied together and they’ve come loose inside. The electricity coursing through it is alternating the magnetic field in it and making it vibrate
[ul]
[li]Be sure to unplug the tv of course.[/li][li]Get a screwdriver with a plastic handle and an alligator clip.[/li][li]Clamp one end of of the alligator clip to the screwdriver and the other to the chassis of the set.[/li][li]Hold the screwdriver by the plastic handle at least an inch away from the metal and push it under the rubber fitting that’s on the surface of the picture tube, and connects by a thick red wire to the flyback. This will ground out the flyback and make sure there’s no charge. Be very careful to not get your hands or body anywere near the metal on the screwdriver or anything else metal, as there’s 25,000 volts in there, and take it from one who’s been hit, you don’t want that in your body.[/li][li]Now unclip the rubber fitting with your hand. You can use a rubber glove if you’re paranoid, but it’s relatively safe at this point. I’ve pulled off literally hundreds of these in my life and never been zapped after it’s been grounded.[/li][li]After pulling it off, touch the metal contacts on the under side of the rubber fitting to the chassis just to be sure.[/li][li]Unsolder the flyback[/li][li]Get another one[/li][li]Solder it in and connect it to the picture tube.[/li][/ul]
There’s no way to fix the flyback by the way. You gotta replace it.
In case I wasn’t absolutely clear, when you push the screwdriver under the rubber fitting, you want to touch the screwdriver to the metal connector that’s under there in the center of it.
I only mention as not doing this correctly could get you zapped.
Especially since modern sets DO NOT have metal chassis, and it may not be at all obvious where ground is. Plus with the set unplugged, there is no ground, so you’re as likely to put that 20-40 kV someplace you don’t want it going. In short, don’t do that.
By the way: technically it may be potentially lethal, but I’ve known alot of people who’ve been hit by the 25k that comes out of a flyback, including myself and I don’t know anyone who’s sustained permanent injury. In fact, I was dumb enough to be hit by 25k once while the set was on, which is far worse than what you’ll get from a residue charge. I repaired TVs in my dads shop from the age of 12. I don’t think I knew anybody in the industry who hadn’t gotten a high voltage zap at some point in their lives.
The most serious case of injury I know of came from when a guy was carrying a picture tube that had been returned to the factory and got zapped by it (the picture tube is effectively a giant capacitor as it’s glass with metal on both sides). He got injured because when he got zapped he dropped the tube and it imploded, giving him some good shards in the leg.
That’s not to say that playing with high voltage is a good idea. Be very careful, and don’t do it unless you have at least some idea of what you’re doing, but it’s not exactly like taking up amateur tiger taming.
Actually, that part isn’t accurate. It’s not an issue that there exists a charge between some point in the set and earth ground. It’s an issue that there exists a charge between some point in the set and ground in the set.
MGibson, if you’re the least bit nervous, or if you haven’t soldered or worked with electricity before, don’t do it. Buf if you’ve got a bit of experience, it’s not all that tough, and if you’re careful, it’s not all that dangerous.
It may be worth noting that to repair televisions professionally, you aren’t required to get any special license or take any special safety course. Like I say, the high voltages in a set can be very dangerous and one should take precautions and know what they’re doing. But it’s not exactly Evil Knievel death defying either.