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timmy 10-06-2022 02:19 PM

Or the 6cg7

timmy 10-06-2022 02:51 PM

Ok vertical is good now so 1st IF no change 3rd IF still got the bars

Username1 10-06-2022 03:47 PM

If your looking to get rid of the bars, I think I would look to the Video Amp,
Video Output, Blanking amp. Not sure I would look in IF for this....

You can yank individual tubes, see if it goes away..... If you still have them
yanking 3ed IF, then it's after that....

In this case, it's good to have a tv with Parallel filaments, just yank one,
and see if you get a significant change....


.....

timmy 10-06-2022 04:23 PM

Quote:

Originally Posted by Username1 (Post 3245360)
If your looking to get rid of the bars, I think I would look to the Video Amp,
Video Output, Blanking amp. Not sure I would look in IF for this....

You can yank individual tubes, see if it goes away..... If you still have them
yanking 3ed IF, then it's after that....

In this case, it's good to have a tv with Parallel filaments, just yank one,
and see if you get a significant change....


.....

Have you seen the pic posted with the bars on the previous page.

Username1 10-06-2022 04:43 PM

http://videokarma.org/attachment.php...7&d=1664286524

http://videokarma.org/attachment.php...1&d=1664977314

I have seen both of these....


.

timmy 10-06-2022 04:46 PM

Oh ok what would make such clean still bars like that I’ve never seen that before.the top pick has bars also but on that top pic if I inject video it looks ok but now I don’t think it would work injecting video now.

Username1 10-06-2022 05:02 PM

Nice clean steady bars like that I would guess are from the Horiz. deflection circuit
getting into the video somewhere..... Either it's picture information with a Dark bar,
or it's a white bar with picture information in between..... What's it look like to you?

Is the light, or dark area got some noise in it?, then the one more solid is the intruder.

At any rate, you are going to have to look back at what you recently did to see if some
part is touching something it's not suppose to...

Since it's well sync'ed to the horiz. to lock like that, it's from the horiz. section of the tv...



.

timmy 10-06-2022 05:13 PM

Well I already pulled all 3 IF tubes and was still there so I guess I’ll be pulling other tubes hopefully I can get this fixed already.

Username1 10-06-2022 05:28 PM

I think you need to look past the IF section for this.... Video Amp, V. Output,
Blanking, that area..... Yank a tube see if it goes away, if so, it's around that area.
Or at least that may be where it's getting in....

.

timmy 10-06-2022 05:30 PM

I don’t know if this would have anything to do with the video and the bars but the focus wire in the crt plug was burned and I had another wire with the end on it so I simply replaced it but the old one I had to dig it out of the plug the hole where the wire fits was kind of beat up but it went in ok but is it possible that it carbon tracked in the plug enough to short to the next pin to it.

Username1 10-06-2022 05:59 PM

I would imagine the focus voltage is pulsed DC at 15Khz, and can possibly be able
to produce bars like that if carbon tracked over to a common K, or G, point.

I had a tv once with Heater to Cathode short or leakage, don't remember how
shorted it was, But it produced white hum bars that floated upward through the picture
similar, but opposite to the black bars you might see in a bad power supply filter cap.

That one I found using the resistance measurement table in the Sams.



.

timmy 10-06-2022 06:48 PM

I know it’s a long shot but it’s worth a very close look at the crt socket and I know the focus wire is kind of separated from either side pins there is a space on both sides of the focus wire and this wire was burned and melted in the socket so it would be nice to find carbon tracking.

timmy 10-07-2022 08:50 AM

Ok no problem with carbon tracking on the focus wire so in pulling all tubes the only one that made a difference was v19 1st chroma band pass amp. Tube pulled no lines tube in with lines.I hope whatever the problem is it’s the reason for no video maybe this is corrupting the normal video path.

Yamamaya42 10-07-2022 09:55 AM

The lines are still there with V19 removed, they are just harder to see, as you loose H-BLANKING, and the screen looks over-driven.

Not only is there the weirdness of the dim screen with reduced width, the bars seem asymmetrical, a bit wider on the left than they are on the right.

Almost as if there was some kind of noise / ringing going on in the bias supply, 385v, as Squirrel boy said, “this might be a job for Mr. Oscilloscope”

Things unknown.

What is causing the loss of horizontal width?
Where are the bars from.
Is there a problem with power? (diode/cap fail causing noise , ripple )
Is the horizontal oscillator at the right frequency and correct waveform.

jr_tech 10-07-2022 12:32 PM

Quote:

Originally Posted by timmy (Post 3245370)
I know it’s a long shot but it’s worth a very close look at the crt socket and I know the focus wire is kind of separated from either side pins there is a space on both sides of the focus wire and this wire was burned and melted in the socket so it would be nice to find carbon tracking.

Very much worth a close inspection, did you replace the socket?
Also did you check for broken/ open wires to the crt socket.

jr


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