: A longshot here, but does anyone know about color television repair?



Red_October_7000
03-04-08, 09:11 PM
So my TV was getting too clapped out to use; naturally this perpetuated a visit to the TV repair shop, which culminated in a used, 1986-vintage RCA Colortrack 2000 (CTC-131 Chassis) with a new picture tube and a $20 price tag. It had been sent in for repair but the owner essentially scammed the shop by leaving it with him after buying a new set and declining to pay the repair costs -this is a common problem in this business. Unfortunately the set is inoperative. The TV shop man won't look at it without money because it was an as-is sale (though he did provide me a service print, it is useless as it is just schematic diagrams without troubleshooting information or even descriptions of the various mechanisms) and to top it off the set is a wood-chassis deluxe model that weighs in at around 200 pounds and I'm loathe to move it again. I'm capable enough with electronics repair (though I've never tackled a television before) so I can say a few things, the fuse and line cord are good, and all connectors are seated well, but I have no idea where to test and what for, even though all test points are clearly marked.

Night Wolf
03-05-08, 03:37 AM
So my TV was getting too clapped out to use; naturally this perpetuated a visit to the TV repair shop, which culminated in a used, 1986-vintage RCA Colortrack 2000 (CTC-131 Chassis) with a new picture tube and a $20 price tag. It had been sent in for repair but the owner essentially scammed the shop by leaving it with him after buying a new set and declining to pay the repair costs -this is a common problem in this business. Unfortunately the set is inoperative. The TV shop man won't look at it without money because it was an as-is sale (though he did provide me a service print, it is useless as it is just schematic diagrams without troubleshooting information or even descriptions of the various mechanisms) and to top it off the set is a wood-chassis deluxe model that weighs in at around 200 pounds and I'm loathe to move it again. I'm capable enough with electronics repair (though I've never tackled a television before) so I can say a few things, the fuse and line cord are good, and all connectors are seated well, but I have no idea where to test and what for, even though all test points are clearly marked.

Keep on rockin the 80's! heh

Sorry, I can't help, but I did forward this to a friend who knows electronics, maybe he can offer advice.

eldorado99
03-05-08, 03:45 AM
I couldn't tell you, but I can tell you this; Be careful in there, there could be tens of thousands of volts waiting to get at you if you touch something wrong! Although you probably know that anyway.

Good luck!

Red_October_7000
03-05-08, 04:31 AM
I couldn't tell you, but I can tell you this; Be careful in there, there could be tens of thousands of volts waiting to get at you if you touch something wrong! Although you probably know that anyway.

Good luck!

Hell yes I know this, though it's not a "hot chassis" set and is much less dangerous than some. A buddy of mine relates a story of someone wearing a metal watch reaching into a "hot" set and crossing B+ to ground with the watch (over 5,000 volts), reaching over his shoulder, and punching him straight in the mouth harder than he could have voluntarily before passing out cold, sending my buddy across the room with two fat lips... and later, much to his delight, home for the day with full pay!

CIWS
03-05-08, 09:09 AM
The highest voltage in there is going to be around the flyback and the anode lead going to the tube, that's usually about 25K and it hurts for a split second. :shocked: I met it once.

Even by that time most of the TV repair had gone to board level maintenance. See if you can find a Sams Photofact schematic for that set and use those to try and shoot some voltages and signals, if you have access to a scope and Sams produced one for that model.

dkozloski
03-05-08, 09:44 AM
There is so much current flow in the sweep circuits and power supply areas of a big TV, the usual cause of failure is that something went up in smoke. If you don't get it completely fixed on the first try it goes up in smoke again and does even more damage. Definitely not a place for amateur hour. The big danger with high voltage in TV sets is not electrocution. It's leaving pieces of meat and skin hanging on sharp edges when you involuntarily yank your hand out after getting bit.

CIWS
03-05-08, 01:36 PM
The big danger with high voltage in TV sets is not electrocution. It's leaving pieces of meat and skin hanging on sharp edges when you involuntarily yank your hand out after getting bit.

HAHAHA :yeah:

heavymetals
03-05-08, 01:49 PM
I worked in the repair business and had my own for over 25 years.

Those old sets are a good source of Xrays to.

What are the symtoms?

no power, no raster, no sound, no pic?

Red_October_7000
03-06-08, 01:11 AM
Set won't power on. It's a "soft" power set, the power switch is a microswitch (I tested it, it's good) and the set won't power up. I've heard that these particular sets had problems with cold solder joints in the control module and that I should look there (seems likely enough, for whatever reason everything else on the thing is socketed but the leads from the switch go into the control module directly. Dissasembly of the module will probably have results. Thanks for all the warnings; I'm well aware of the many kilovolts inside a TV set that are NOT hapy to meet me. Fortunately this is not a "Hot Chassis" set and won't bite unless I do something monumentally stupid.

ewill3rd
03-06-08, 08:38 AM
Personally... these days... I'd just go buy a new set. Sure you got it for 20 bucks but by the time you invest your time and energy into it you could have gone out, bought a new set, and done something to make twice as much money. I am all for fixing stuff, but if you don't do it for a living you basically have to teach yourself a whole new trade to do it. Even the TV repair guy refused to invest his time into it and he knows all about it, presumeably.

I am a victim of a high voltage jolt from a TV set. I can't tell you how much it was, all I can say is I stuck my hand in the back of a Magnavox from the '60s that made the lights in the house dim when you turned it on.
It had a "push off" power/volume knob that popped in when I went to turn the set off.
Being a smart kid, I didn't want to unplug it to shut it off for fear of damaging the TV, so I twisted the retainers on the back, carefully removed the back so that the power was still on and fed my hand into the back of the set. I pushed the volume knob into place and got hit by something that made me scream involuntarily and yank my hand away and I tore a huge gash accross my hand on a metal plate inside the chassis.
And I consider myself lucky!

TV's are too inexpensive these days to spend time and money on something to get it working... only to have something else fail a few months from now.
I have replaced a few transistors and circuits in TVs only to have them crap out later and make me wish I hadn't wasted my time.

If you decide to keep going, more power to you. Just thought I'd share my opinion.
;)

dkozloski
03-06-08, 09:19 AM
Power supplies in big TVs seem to work by magic. Back in the day there were 25 lbs transformers and big rectifiers but now it's switching power supplies and magic. One good surge and the whole works is wiped out. What isn't destroyed is damaged. Even if you could get it going it wouldn't be something you could trust.

NOT ON MY WATCH
03-06-08, 01:27 PM
Will that TV even accept digital broadcasts? If not, I'd say that's a poor use of your time, unless you really want a new hobby. If you really need a new TV, you can find used tube models for $100 or so that actually work.

Also, I notice that you're researching this on forums where there might be a few more resident experts. Good luck to you.

http://www.badcaps.net/forum/showthread.php?p=46767#post46767

The internet can be your friend...

:)

Red_October_7000
03-06-08, 02:32 PM
Well first of all a few things: I want this set to work for a number of reasons. First of all it's 200 pounds and I'm loathe to move it. Second of all it's a wood chassis set and is actually square, meaning I can put my cable box on top of it; it kept falling down in back of the newer, plastic body set I used to have. Third of all it looks nice and is a much higher quality set than anything out today; it has a full-range NTSC tube and as I don't have anything but NTSC sources I don't need HDTV, and as I have cable, the digital crap they are pushing will be of no use for me, not that I believe it will actually go through. Furthermore modern sets are ugly and made in foreign lands. This is an American made set. Finally, I've invested lots of time into this set and I'm not prepared to give up.

ewill3rd; the set you reached into was a hot-chassis tube set; they bite and they bite hard. The interlock on the back is for a reason. Granted everyone had a cheater cord, but the implication was at least that by putting on a cheater cord you at least knew what you were getting into...

heavymetals
03-06-08, 02:54 PM
If you have +5 on the power switch it means the low voltage/logic is working.

On these type of sets they have what's known as a "bootstrap" where the set gets its various voltages from the flyback.

You will find out why it is called a flyback when you get zapped!

Sounds like no horizontal oscillator.

Usually it is the horizontal output xtr.

I had one customer who wouldn't give up the "beautiful" cabinet and had it made into a fishtank.