1979 GTE Sylvania GT Matic CX9164W chassis E24-3
 

Just got this set in a lot of 4. This one was a huge mess. Got it cleaned up but the plug is cut off at the end of the cord which isn't a problem but I'm hesitant on testing till I know more about the flyback on it. There is a small bulge on top with some cracking and one edge is warped a little. Will it hurt to try or should I replace that 1st? I've circled the areas.

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You gotta work on the pix sizing ! Dont feel bad, I wouldnt know how to
do it either !! I would ask my sons but I would forget in a few days.
Anyhows
It looks like an in line jug. Thats good as the earlier GT matic / Super Set
deltas had a VERY short life. If it were me I would just fire it
up with a variac. You need to confirm the CRT is good BEFORE you
put time & $$$ into it. Post some sized pix of the area also first. All
I can see is what looks like a chunk out of the FBT.

73 Zeno:smoke:
LFOD !

I know. I never had trouble till now. Not sure what's going on but I'll getting better ones.

Ok, I think I got it. Phone has a resizing option but I never had to use it.

The small thing in the first pix looks like a spark gap. 2nd pix
looks like a tripler that is cracked open & NFG. Dont run it.
After the week end I will see if I have a manual & give more info.

Zeno

Ok, I'll wait 👍

Those were made from about '75 until '80, when they were replaced by the E32 single-board chassis with an IHVT.

On your set, triplers were a high-failure part, as well as the filter capacitor and bad solder connections. I ran into a few bad yokes and a number of weak tubes on these. When they're right, they have a nice picture. I think the tripler on these is an NTE523A.

Looks like it. $25. I'll try to order that soon.

Also, what is the filter cap on this? May as well replace with the tripler.

New tripler arrived today. Will put in today or tomorrow and update.

Put new tripler in and tested. Red breaker on back popped out tripped where do I look now?

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?

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.

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.

One thing I learned on an SCR sweep RCA is if the breaker is tripping and you want to know if it's the trippler or not just unhook the flyback output from the trippler input and stick the lead in a jar so it won't arc. If the breaker won't trip like that the trippler is bad, if still trips you have other problems....
You can do the same test to check the trippler if the set isn't tripping the break, but isn't making HV... Only you want to monitor Boost voltage. If it's very low with the trippler and normal or high without the trippler loading it then the trippler is bad.

This tripler is new from DigiKey

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

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

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

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.

Ah, ok, I'll check and update.

I'm not getting anything with it out. Just the #1 at far left.

Your meter has a diode / transistor test, the diode symbol.
Look up that function in the manual, too long to type out.
OR look for some tubes teaching it. You will be using it !

Zeno:smoke:

If the transistor is reading open with it out of circuit, then something else is wrong. If this has a separate damper diode, the diode would be the next suspect because of the punctured tripler. Note that some transistors had the damper diode built in. Yours being an earlier SS design probably has a separate damper behind the horiz output socket (most) or on the main board close to the horiz output.

Is there a schematic on-line? (I scrapped all my paper schematics and most of my SAMS about 15 years ago)

John

I'll see what I can find.

I can't find a schematic and I have no idea where the damper is on this 😞

The diode damper probably will be the largest cased diode near the flyback, connected at least to some pin of it, sometimes in parallel with HO transistor, and other side (cathode) generally is ground on simple TV's (if is separate, like John said).
Of course, for some TV's, other or others diodes can be associated to primary winding, but is more common on newer TV's (like supply for RGB video output). So is good to check diodes nearby the flyback to be sure.
Another potential part suspect can be the pulse capacitor, the one that tune the flyback pulse, and is rated at least with 1600V (some nF), also near the flyback, and probably at same line with HO transistor. Polypropilene on newer TV''s, and perhaps something-with-oil on older TV's. Normally this fails open, but to be sure, is good to check.

It might be right on the back side of the socket of the horiz output. It can either be a black barrel body or a grey round ball - either will have fairly thick leads.

Electrically, the cathode of the diode will be connected to the collector (metal case) of the horiz output and the anode connected to the emitter of the transistor (ground). If you look behind the socket, it should be there.

If it's not, trace the wire from the collector (screws are collector) to the main board to locate the diode.

Clip or unsolder one end, reinstall the horiz output, and see if the short to the case is gone. If it is, the diode is shorted but do NOT run the TV without the damper connected or you will immediately destroy your horiz output which right now is still good.

John

Ok I'll check later today and update

I have the console version of this TV, mine still works yet suprisingly enough but its missing the "lock" for the front panel that opens up for the user screen adjustments so the user screen adjustment door is open all the time, which is also where the speaker is so the audio doesn't sound very good because the cover isn't properly baffling the speaker.

Can't find anything in that mess. So much going on in there. I took a few shots hoping someone recognizes something. I see the back side of the output, screws and wires running down.

Yes, seems to be difficult; too many wires and so on. The solution is to follow each flyback wire, and see what ones ends at diodes, to measure them.
Not seem to have any diode in the HO transistor socket.
I sse some relatively fat diode near the socket with "24" number on it. Is impossible to know if is relative to flyback, without following the flyback wires.
Sometimes, in the hurry, I simply measure every diode near flyback at time I'm worked with TV's (is faster anyway).
The suspects are removed and measured externally to be sure.
I see one small diode in parallel with a small capacitor in one photo. These one seems to be improbable, but anyway, is good to check on the DMM diode scale.

Other thing, since manufacturers not want to use 2 times same funcion component, is good to measure on diode scale the HO transistor you removed from TV. Measure from collector to emmiter. In one side, basicaaly with negative (black) proble connected to collector (case), and negative to emmiter, the DMM will measure something between 0.5 and 0.8, and, for another side (reverse, with red onde connected to case), will measure OL. If measures this manner, the damper diode is internal/integrated to transistor case.

I have same problem with my 17" Toshiba from 1987; the controls are exposed (the "lock" protuding part broken). I need to solve it before the grandchildrens visits here ;)

There are three wires on the back of the horiz out socket. The wire that's attached to one of the screw posts is the collector. Follow that down to the board where it will be connected to the damper diode assuming the TV has an external one.

What is the part number of the horiz output?


John

I can't find any numbers on that output. Maybe if we could figure out which one this chassis is designed to use.

I scrapped all of my GTE/Philips schematics years ago along with most of my SAMS of those years.

If anyone has any SAMS still, it's in 1751 folder 2.

John

Sams 1751-2 shows the damper diode as "SC448". It's on the circuit board between the yoke socket and the focus control area. It's between the horizontal linearity coil, L470, and a large cap labeled C448. Sorry, can't post pictures.

And I just remembered the diagram is on the inside of the back cover showing horiz output is Q402.