I've had this General Electric(Has GE logo on all labeling but inside says RCA) 20GT370 (20" "Stereo Monitor") since 1992, it's been a champ over the years, surviving multiple moving trips with relatively few problems/damage. However the last few years it's begun to suffer "Wiggle Syndrome" where you have to wiggle/twist one of the RCA connectors until the signal doesn't go out. I know that this is caused by the solder cracking/etc right? I've done repairs on other electronics by re-soldering cracked solder before that had loose connectors causing problems, except that I have 0 experience or knowledge of CRT Tv's. I opened it up and was greeted with this http://img690.imageshack.us/img690/4632/dscn5663s.jpg To be honest it was almost kind of frightening, near 20 years of dust build up and it looks like part of the bulb/glass attached to the electron gun has broken through the tape and is bulging(or is this normal?) Does the TV need to be discharged before I can go and get to the underside of the PCB so I can resolder the RCA connectors ? I would assume yes, but I want to double check. Or should I just put the case back on and never take it off ever again. :O:gravedigging: ALSO:I didn't know if this or the preservation section would be the right place considering this is not a Video Game System or anything like that. So *shrug*
You can probably repair this by not actually removing the chassis, unless the RCA input(s) in question are on the front of the set, and not the rear. If they're on the back, you won't need to discharge it (just make sure it's physically disconnected from the mains), as you won't be coming into contact with the high-voltage areas. Keep hands away from the PCB solder-side as a precaution. If you find the RCA socket itself is actually worn-out (rather than dry-jointed), you should be able to find a suitable replacement online, or you can hard-wire in a 'female' RCA extension cable instead. If the input sockets are mounted on their own PCB (or daughterboard), re-solder the connections there as well. The tube neck is normal, there's usually some glue and lots of additional bits sticking out. I wouldn't attempt to poke around with these, as there's a good chance you might accidentally offset the colour balance of the tube itself. To get to the rear inputs, you'll have to slide the chassis out. There's usually one or two retaining clips along the sides of the board. Once unclipped, it's probably best to turn the whole set on its side (and lean the front against something), so you can view the solder-side a bit easier (unless of course you can flip the board over with relative ease - some designs are more repair friendly than others). You might have to unclip one or two of the wires as this will help the board to slide out a bit easier, but make a note of where they go before you do this. Please note that all CRT TV's are front-heavy, so naturally be careful when moving the set around as it's more likely to tip forward with the back removed.
You need to be very careful when opening a CRT. Supposedly parts of a CRT can hold a charge even when it's been disconnected from a power outlet.
I always assumed that turning it on after it was disconnected from the mains would drain the rest of the charge. Was I mistaken? If so I'm lucky I'm not dead....
I don't know about that, but even if that'd theoretically work, it's not surefire - I think some CRTs use a small computer to handle controls like the power, so pressing the power button might not do anything at all.
I've always had a "I'll have a go" attitude when it comes to repairing electronics but I've never even tried to repair a CRT tv or monitor, must be the memory of my dad flying across the living room after a unsuccessful repair attempt of our tv...1987 if memory serves correctly xD. BE CAREFUL!!!
I'd say the only real danger (apart from dropping the thing on your foot), is from the big red cable going into the top of the CRT. I would strongly advise against poking around here as there's a good chance that there's still a charge present under the suction cup. The glass of the CRT acts like a big capacitor, so unless you know how to discharge it safely it's best to avoid. If the set has been unplugged for more than 48 hours, I'd say any residual charge inside the capacitors would've fallen low enough not to be harmful. On saying that, I would still avoid high voltage rated capacitors in and around the power supply areas as a precaution. The obvious one, don't run the set with the back removed! Some TV's have a live chassis design, which means that potentially all the exposed metal work on the chassis (minus the tuner) is potentially live. Even most experienced TV engineers will never work on a live TV chassis without the use of an isolation transformer, and will always keep one hand in the pocket to avoid the worst-case scenario of electrocution across the chest region (heart). Yes that trick works for much simpler electronics, but something more complex like a switch-mode power supply it's not always the case. Hence all the nice warning stickers and groovy lightning bolts illustrations. Often you will find these on PCB markings in the PSU areas, right around the high voltage (250v to 400v) reservoir capacitor(s).
Thanks a lot man, I'll give this a try. And I will also try not to touch ANYTHING other than what I need. I've also got a desk I can set the face of the TV on so that'll work. Thanks for the help everyone. I'll let you know if I can get what i need. Edit: Well, I gave up. Couldn't figure out a way to get the PCB without taking everything apart. Thanks anyways guys.
Sorry, but you've had some bad advice here. Televisions don't supposedly maybe hold a large charge even when off. They DO hold a large charge even when off. 20-40kv, actually. And no, it's not "just the red bit". The tube will hold the voltage, but the tube is connected to the LOPT - all of that circuit will hold high voltage, and that can include some other parts, too. If you don't know what's what, don't go poking around in there! The television looks normal in there. Don't go dusting, you will probably do yourself some damage if not the TV! And yes, unless the components are on a low voltage board that you can GUARANTEE will detach without risking damage to yourself, you need to discharge it first. And the golden rule if you must poke around, never EVER put both hands in there at once. Keep one in your pocket.
Listen to Retro on this one, he's right on the money. CRT monitors are fucking deadly. If you really are going to tinker with one, make absolutely sure you know 100% what you are doing, and don't be stupid. Fucking with a CRT without expertise in this sort of electronics is Darwin-Awards caliber stupid.
OP was already warned of the dangers. OP has given up on the repair. Stop being such a girl about it ;-)
lol. Guys, I was already aware of things like the "hand in pocket rule" So, no worries there , as well that other things still have a charge(which was why I was planning on touching NOTHIN but what I needed to get to. But I digress, I've given up. I was scared to even get close enough to look at all the circuitry lol, and I couldn't figure out how to get the PCB out without disconnecting stuff that was hard-wired to the board. part that sucks is, who even Services CRT's these days? Probably almost nobody. I guess I can deal with the waggle. But, I have another TV that is not nearly as old(by about 7-10 years younger) that has a dead composite input in the back and the front has even worse "Waggle syndrome"
I imagine it being all like this: http://www.youtube.com/watch?v=qs2Hjh4F7nY Barely anybody. Most you ring up will say ''get a new LCD telly'' because the price it costs to repair a CRT isn't worth it.
Don't Give Up No worries soldering the RCA connector. Just keep clear of the back of the CRT and Flyback Transformer connected to it. Think of the tube as a large capacitor or charged up battery, one with enough voltage to kill you. There is a way to discharge by grounding the Flyback connection at the tube, but a dangerous risk and also damaging the equipment. Just leave the TV unplugged for a few days before doing any the solder work.
My first thought was this: http://www.youtube.com/watch?v=JiBSrocGagM Back to the OP: my advice would be, just get another CRT from a thrift store. You can usually get one for around $20, sometimes less.
