skier

yeah, another dead TV thread.

Alright. I have this 20 year old TV that's just gone quits on me. It's an RCA colortrak from '85... Holy crap, this thing's older than I am.

Anyways, it moved up with me from my parent's basement last year to my apartment. About 5 months back the screen began to flicker occasionally. I figured no problem, it's an old tv, things happen. But about 2 weeks ago the flickering got longer and longer until the crisis point yesterday. I had figured out that slapping the top of the TV restored the loose connection or whatever it was and it stopped the flickering for a while (20 minutes). But yeasterday I hit it and it just died. Totally.

What I want to do is take it apart and look for that loose connection so I can solder it back together- and maybe fix my TV.

I wanted to ask about what sort of things I should watch out for in this old TV. Capacitors, anything that could be holding a charge and zap me. Also, if I could ground them without damaging anything.

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Craven Morehead

don't take it apart, you could fry yourself if you don't know what you're doing

superiorrain

As long as it's unplugged then you'll be fine right?? well thats what i think. What i would sugguest is hitting it a few more times. I had this great TV which died on me so often, but with a quick wack it would jump back to life.

Use a electrical screw driver that will protect you from frying, either that or put on some rubber shoes. Once you open it though i have little hope for you being able to fix it, but a good clean out of the dust may help.

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cyrnel

Great way to a new hairdo.
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vinaur

Unplug the tv and let it sit for few hours (maybe a day) this will make all the capacitors uncharge. Afterwards, have fun. Don't get your hopes up though. You'll probably end up throwing the tv out.

jujueye

Good advice. BUT MAKE SURE YOU CAN IDENTIFY A CAPACITOR. Seriously. Anything with a transformer onboard can change the whole "fiddle with it" mentality. If you have a multimeter, test all connections first. Yes, most caps discharge, but larger ones will take longer. If they are grouped, they may take longer to discharge.

Personally, I don't think it's a connection you can fix. My 1989 RCA did the same thing a few years back. After calling around I found out it was a $200 part or something. Drop it off at your nearest repair shop and let them part it out.

Good luck and be safe.

skaven

Generic TVs at Wal-Mart are super cheap, and will have a much better picture than a TV from '85. Not to mention luxuries like RCA inputs and the ability to move the TV around without a furniture dolly. Don't waste your time trying to fix that TV, unless you really just want to dink around with the hardware.

As for safety issues....there are lots of capacitors in TVs that hold a charge for a long time. The CRT itself also holds a hefty charge and can probably kill you. I don't know how long it stays hot, though.

Another bit of wisdom: old-skool TVs do really awesome things when dropped from tall bridges into water ;-)

dirtyrascal7

i agree with skaven... i think it would be money and time well spent just to go upgrade to a new tv, even if it's one from wal-mart.

flat5

Stay away from the CRT high voltage line. It's the thick insulation wire with the
rubber cap at the end. The CRT will hold 26000 volts for many months if dry.

What you are first looking for are heavy components mounted to the circuit board
by the leads. No screws. These will loosen in time. Also, check components that will get very hot. These connections to the pc board may go bad in time. Train your eyes to see a round thin "line" around the pc "pad" (where a component is soldered to the board).

If you have to deal with the high voltage section (where that wire with the rubber cap
goes) you can discharge the CRT with a long screwdriver. Attach a clip lead to the screwdriver and the other end to the high voltage cage (metal) or to chassis ground.
Then stick the end of the screwdriver under the rubber cap and into the whole in the CRT that the wire fastens to. Keep it there for a few minutes. One quick poke will not discharge the CRT. The charge will return! but less so.

Important! When doing this discharging routine, USE ONE HAND only. Keep the other hand in a pocket or somehow away from any conducting surface or TV componants.

If this does not make sense to you, forget the project :-) IMO

Good luck.

skier

Wow! thanks for all the advice guys!

I have basic knowledge of electric stuff. I used a monitor once as a transformer to power a lifter (lifter site) and I realize the power that an old TV could have even a long time after it's unplugged.

flat5, I thank you for your excellent advice. Yes, what you're saying makes a lot of sense- and you've definetly given me a better idea of what i'm looking for.

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ZërØ¢ØØ£

and to go along with flat5, do NOT use an esd strap(in other words, ground yourself) while working with CRT's, you are the potenial path to ground if you do.

but most likely with a TV that old, the CRT went out and it might be cheaper to buy a whole new TV.

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spillblood

just take it to the top of a building and down it. nothing good can come from this but damn is it fun.

d4in

i have taken old tv's like that to a local repair shop and had them fixed for under $40 with parts and labor. Depends on how much cash you have but if on a tight budget, that might be the way to go.

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kurty[B]

you could do what I do... drill a hole in it, fill it with gasoline, light it on fire and drop it off a very high set of high school bleachers. All of which I realize is very stupid and very dangerous, but at least I have it on video tape!

RonRyan85

JUNK IT and buy a new one! New TVs are not very expensive and if your
old one is over 10 years old, the picture tube is worn out and all of the
capacators are shot. Unless you are an experienced TV repair guy you
are asking for trouble and a lethal shock trying to fix it. Back in the black
and white TV days a lay person could fix their TV sets by replacing most
of the weak tubes and not run into much trouble. Not any more. Go buy
another new set and give your old one to the garbage collectors!

flat5

The reasons to try to fix it is to learn something, the satisfaction of fixing it yourself (if you do), to save the set and money, and because you enjoy playing around with electronic stuff. This is not a waste of time for many of us.

Many TV sets work for over twenty years. This one might be worth fixing.
Good quality capacitors should last as long as any other componant in the set. High voltage componants are stressed the most. These have to be of good quility to last as long as other componants.

I forgot to mention using a wood or plastic rod (drumstick or tooth brush) to tap
lightly around and watch the CRT for changes. This is very useful for finding intermittents. Of course you do this with the set ON and tuned to a station.
This can help you focus on an area to look at closely.

zen_tom

I turned an old b&w set into an oscilloscope that I wired up to my hi-fi speakers - CRTs can do more than just display a TV signal.

skier

This is the attitude I had in the back of my mind, I couldn't really express it though. It's kind of like how some guys like to fix up cars even when it may cost them more to do so.

I already have a newer set, but I love to look and poke around with electronics. I fixed my 5-disc CD player by doing so, and have taken apart lots of gadgets that were beyond hope. It's sort of a way to understand the science... lots of things in our world are almost beyond our comprehension. We just know they work, but not how. I find it comforting to take apart that mystery, so i know how the stuff around me works.

I want a better understanding of basic electronics, I don't really know where to start though... I had a physics 30 (high school) professor that was into that, maybe I could go look him up :P

Anyways, again, thank you for the advice, I just gotta get to my parent's place to pick up my stuff (soldering equipment and the like) and then i'm going to have a look.

__________________
"Asking a bomb squad if an old bomb is still "real" is not the best thing to do if you want to save it." - denim

portereight

My father used to be a television repairman from the days of tubes until the mid '80's. I recall that televisions that had been left unplugged for long periods could still hold a deadly surprise.
Don't venture where you are unsure. Advise from a forum may be qualified and well intentioned, but you really could come to harm inside a television from that era.

flat5

For the record, my father worked for a Packard-Bell TV repair shop in the 50s-60s.
Back then, the company made good stuff :-)
I studied television repair at a trade school in 1970.
I have discharged CRTs and replaced them.

sashime76

Give it to Salvation Army or some charity, maybe they can have a tech fix it up for free or turn it into an aquarium. TV that old doesn't worth the salvaging.

irateplatypus

if you want to learn more about electronics there are far less lethal ways than poking around an old crt.

my advice: leave it intact so as not to fry an unsuspecting garbage man and toss it away. what you learn from a 25 year old set isn't worth the trouble when so many other interesting/inexpensive projects are to be had.

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hunnychile

The aquarium idea is pretty cool, or terrarium is even better! Have fun...

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skier

Just as an update, finished playing with the tv, redid a few solders, and it works again

__________________
"Asking a bomb squad if an old bomb is still "real" is not the best thing to do if you want to save it." - denim

flat5

Good for you!

BTW, you can learn much about electronics by Googling on a specific subject.

also

Find an old edition of "The ARRL Handbook".
It has been published every year since the 1930s.
Librarys have them, if not stolen!

Maybe it used to be called "The Radio Amateur's Handbook" in the early days.
Great book to browse or study. I prefer the ones from the 40s-70s for browsing.

tehhappyboy

OH GOD OH GOD
There are some terrible suggestions in here. Televisions are extremely dangerous for months after they have been plugged in. The discharge instructions were okay, but it's really important to have a good grounded screwdriver attached to the chasis if it is plugged with a grounded plug or somehow attach to cold water pipe. There is a reason the wire insulation is really thick on that one. Make sure you are NOT a path to ground for it's discharge. Three or four pokes should discharge most televisions with a nice crackpop. Problem is any TV with a microprocessor in it is unlikely to be fixed without replacing the whole thing.

Once that is done, it's pretty damn safe.

Other notes: to fix a tv when a kid attaches a magnet to it: You need a degaussing coil that has a random magnetic field and it will fix the little mesh screen that separates color phospors (wires on a trinitron).

TVs are tuned in a neutral magnetic field to counter the earth's effects on the beam. (different positions on a tv change it's performance over time).

HDTV sets have lots more adjustments in software to adjust the picture.
---------------------
When your television set breaks down and needs repairing bad,
lotsa luck pal, lotsa luck.
You look through the yellow pages for an honest looking ad,
lotsa luck pal, lotsa luck.
When you call him he will say your set must go into the shop,
and he takes it, in his truck.
Three months later when he brings it back it's someone elses set,
besides he drops it down the steps so lotsa luck.
-Allan Sherman

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