73 Zenith Chromacolor II no picture

I just picked up a 19" Zenith Chromacolor II tv from a guy. It was made 4-3-73. The chassis # is 19EC45 and its solid state. We had it working at his house but it looked like the tuner needed cleaning so when I got it home I took off the back and sparyed the tuner and dusted the inside. Well when I got it upstairs I turned it on and it immediately made a poping sound and a burning smell. I looked inside and turned it back on. The horizontal output transister gets hot real fast and I noticed a little black resister connected to it is burned and loose on the wire. Is that my problem or is there more probably wrong?
John

[Don Lindsly]

First make sure that a screw or part has not dropped onto the chassis from earlier work. Zenith terminal lugs are easily shorted out from dropped metal parts. Seems basic, but I learned the hard way.

[zenith2134]

I would check and replace the resistor, personally. Good luck with the set, the SS zeniths had awesome pic's..

[Chad Hauris]

Make sure you get to the bottom of the short/overload before you replace the resistor. You may have a shorted horizontal output transistor, probably best to remove the transistor and check it. Caution as there is usually pretty high voltage on the metal case of the transistor (collector).

[JCFitz]

That "resistor" sounds like a ferrite bead.Probably looks burnt because the glue they use to keep it from vibrating gets hard and turns brown.The only resistors in series with the horizontal output transistor are a wirewound 10 w in the bottom rear of the chassis (usually 10 ohms) and a 1.5 ohm in the emitter circuit with a 47Uf capacitor across it in the emitter circuit of the transistor on the rear of the chassis near the horizontal drive module.Both were high failures.The 1.5 ohm fails because the 47Uf capacitor dries up.There will be no high voltage if the wirewound opens so the transistor won't run hot but the other resistor and cap don't open totally so you can get reduced drive and width and the transistor can run hot.Most likely if the output transistor is getting hot the tripler has failed.They fail rather suddenly.Be careful of powering it up in this condition as the shorted tripler can take the flyback with it.The easist way to test is to unsolder the high voltage lead from the flyback to the tripler and move it as far away from the terminal and any other terminals or metal as possible.Then fire the set up.You will hear and possibly see corona from the flyback lead but the transistor will run cool if the tripler was shorted.If it still gets hot need to check for other problems.If the flyback is also warm or hot then it's bad.Replacement triplers can be still be obtained for these sets.

Where is the tripler located? I also noticed there is blue arcing in the neck of the picture tube. Will the tripler cause that?
John

[Chad Hauris]

The tripler is connected to the output from the flyback transformer, I believe it is on the horizontal part of the chassis which is located behind the mani vertical part of the chassis. You might have to loosen the chassis mounting bolts and pull the chassis back to see it...Arcing in the crt neck either means a bad CRT or that the crt is not grounded properly. Make sure the grounding straps to the crt degaussing shield, picture tube socket and chassis are all connected.

Also it seems like if the focus voltage is missing but the HV is there, there could be arcing...this might be caused by the tripler.

I looked at that tv again. I disconnected the flyback from the tripler. I turned it back on. The arcing in the crt neck stopped and the transister didnt get hot so the tripler must be bad. I also saw the carona from the flyback lead so it must be good. What is the cost of a new tripler and is this set worth spending the money on. Would a used tripler work or is that a part that is better off being new. It was free.
John.

[3Guncolor]

If the set had a good picture before it failed I would try the tripler. I looked it up and it is Zenith part 212-141-01 or ECG/NTE 523/3306 or 526A Used ones will work if they are the correct one. As I remember any of the 212-141 dash 1 and above will work. I think they went all the way to dash 5.
I just changed a tripler on my 78 J line Zenith these were some of the best solid state sets Zenith made. My favorite for solid state is the "74" 25EC58 chassis.

[JCFitz]

After you said you had blue arcing in the neck of the tube that is worrysome.If you disconnected the tripler it would have removed the high voltage from the tube therefore it would have stopped the arcing.Just for a test reconnect it and unplug the socket from the CRT.If you hear high voltage arc from the neck or can bring a grounded screwdriver(preferably a long one to keep your hand away from it near the pins and draw an arc your crt has aired) If you don't get an arc maybe the tripler was arcing and putting too much focus voltage on the tube.If you hear the tripler arcing then that was the case.
Just curious if the 4 lead safety cap is an orange one or not.If it's got the old white one then it probably failed and took the crt with it.Better make sure your CRT is ok before purchasing a tripler.

[kc8adu]

Originally Posted by JCFitz

After you said you had blue arcing in the neck of the tube that is worrysome.If you disconnected the tripler it would have removed the high voltage from the tube therefore it would have stopped the arcing.Just for a test reconnect it and unplug the socket from the CRT.If you hear high voltage arc from the neck or can bring a grounded screwdriver(preferably a long one to keep your hand away from it near the pins and draw an arc your crt has aired) If you don't get an arc maybe the tripler was arcing and putting too much focus voltage on the tube.If you hear the tripler arcing then that was the case.
Just curious if the 4 lead safety cap is an orange one or not.If it's got the old white one then it probably failed and took the crt with it.Better make sure your CRT is ok before purchasing a tripler.

and that set is in the timeframe the white caps were used.
you are probably screwed now
this cap is tywrapped to the hot heatsink.
if it was upgraded there will be a sticker on the back about the 4lead capacitor upgrade.
i got an nos 19vdzp22 on ebay for 25.00 shipped so you might still save the set.

The crt cap is orange. The tube worked fine in the guys shop. The picture was snowy and out of adjustment. It didnt start any this till I got it home and hooked it up. He said it hadnt been used in a while.

[3Guncolor]

Good point about the CRT. That chassis 19EC45 may not have the 4 lead cap but it can use 4 caps on the horiz output to hold down the HV. I just looked it up in in Zenith's service information. As I remember it was the "F" line that used the white 4 lead cap. The caps that chassis uses do fail and can take out the CRT. I just had to change them on a set I had in storage for 10 years. Lucky for me the did not let go all at once.

If the flyback is disconnected from the tripler will that kill power to the crt neck because after I disconnected it the crt neck doesnt do anything. The crt may be shot too. If thats the case I might as well junk the set.

[JCFitz]

When the tripler is disconnected are the heaters glowing in the tube?If it has the orange cap I don't see how the CRT failed just like that unless you bumped the neck or socket accidentally.If the tube is aired usually the heaters won't glow or will be very dim.One thing you can do before condemning it is to mark the position of the yoke and blue lateral assy on the neck before loosening any screws and then slide them off carefully.If the tube arced over you will see the star point in the glass and sometimes the neck will come right off with the yoke.Then you know for sure.