1979 GTE Sylvania GT Matic CX9164W chassis E24-3

[pac.attack76]

Originally Posted by JohnCT

Did you check the horiz output transistor for Collector to Emitter short? If the tripler is punctured it would have arced out and likely damaged the output and possibly the LV regulator.

John

No I didn't. Can u point those out to me?

[JohnCT]

Originally Posted by pac.attack76

No I didn't. Can u point those out to me?

The horiz output will be located on the right side of the chassis near the tripler. One of your pictures shows a metal TO-3 (top hat) transistor held to the side of the chassis near the yellow label with two 1/4" screws. If it's on the right side of the chassis, that's the output (if it's on the left, it's the reg). You can check from the metal body to the chassis ground side rail. It should read open (over 100K ohms). If it reads short (a few ohms or less), the transistor is shorted.

The low voltage regulator would be located on the left side looking from the back. That also might be a TO-3 metal transistor mounted like the horiz output is. That transistor won't be shorted to the ground panel but you can test it by removing it from the chassis and checking resistance between the metal body and the two terminals.

John

[pac.attack76]

Originally Posted by JohnCT

The horiz output will be located on the right side of the chassis near the tripler. One of your pictures shows a metal TO-3 (top hat) transistor held to the side of the chassis near the yellow label with two 1/4" screws. If it's on the right side of the chassis, that's the output (if it's on the left, it's the reg). You can check from the metal body to the chassis ground side rail. It should read open (over 100K ohms). If it reads short (a few ohms or less), the transistor is shorted.

The low voltage regulator would be located on the left side looking from the back. That also might be a TO-3 metal transistor mounted like the horiz output is. That transistor won't be shorted to the ground panel but you can test it by removing it from the chassis and checking resistance between the metal body and the two terminals.

John

Ok I'll check and let u know.

[pac.attack76]

Ok, I set my meter to 200k and tried the one on the right by the trip and I get nothing. 00.0 and I took the one on the left out and nothing on that one either. Hope I did it right. I have a pic of the one from the left.

[JohnCT]

Originally Posted by pac.attack76

Ok, I set my meter to 200k and tried the one on the right by the trip and I get nothing. 00.0 and I took the one on the left out and nothing on that one either. Hope I did it right. I have a pic of the one from the left.

Let's be a bit clearer here - a reading of 00.0 on most DMMs means a dead short (you can replicate that same reading by shorting your leads together).

I've seen more than a thousand shorted horiz outputs in my life, and they all will short "hard", so if your meter isn't an autoranging type, put it on 200 ohms or 2K if that's all your meter has.

If the transistor is not shorted, then it will read the same at 200 (or 2K) as if you didn't connect the leads at all, figure something like OL on the display (means overload).

So if your meter is reading OL with the leads off and 00.0 with the leads on the horiz out, the output is shorted.

If your meter reads 00.0 with the leads open, the meter is bad.

John

[pac.attack76]

Ok I set at 200 and I show with leads not touching, then leads touching, and then leads on output and chassis.

[Alex KL-1]

Very low, for sure a damage on HO transistor (more probably) or something very close (damper diode, capacitor, PSU)

[JohnCT]

Originally Posted by pac.attack76

Ok I set at 200 and I show with leads not touching, then leads touching, and then leads on output and chassis.

Something is shorted, although 11 ohms is an odd reading (most horiz outputs short to ground at an ohm or under), but the transistor remains the most likely cause, particularly with a punctured splitter spitting high voltage around.

Remove the transistor's 1/4" screws and remove the transistor by wiggling and pulling upward. Careful if you have to pry because there's a thin mica insulator between the transistor and the frame that can be damaged.

With the transistor out, check the resistance from the metal case of the transistor body to either of the two leads. If you're getting that 11 ohm or under reading, the transistor is bad. If the transistor reads the same as open leads, the problem is elsewhere.

In any case, an 11 ohm reading from the collector case of that transistor to the ground frame means the breaker will trip immediately.

John

EDIT: your DMM doesn't use the Fluke style "OL" to indicate an infinitely high (open) value but uses a "1" two places away from the decimal to indicate an "open" condition. Same thing, different display method.