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.

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...



.

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.

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....

.

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.

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.



.

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.

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.

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.

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

jr

I am still of mind that the loss of width is a key to the problem somehow, just what is going on exactly, I'm not sure.
http://www.videokarma.org/attachment...1&d=1663858736

There is a noted loss on both left and right sides of what he had before of about 1/2 inch with or without any video input.

this just can not also be related to the bar issue.

Blanking tubes can cause some strange problems. Try one ( 6BL8 ? ).

CRT sockets often go bad on the focus pin. Especially with excess F
voltage over time. They usually smell, problem is the spark gap.
Sockets are all pretty much the same. ! K resistors then the CRT
connection & the spark gap. Sub almost any to test BUT be sure its
off a high focus ( 6KV ) set.

As I remember no scope or analist. Means you you cant trace or inject.
In the day almost every set was fixed with just a Simpson 260 BUT
once in a while you had to get out the big guns.

Zeno:smoke:

I disconnected the focus wire altogether.

I went over everything I did which was not much just a lot of checking nothing touching anything I have a hunch I have another bad cap.

Hi!

I'm wondering about this pic:

http://www.videokarma.org/attachment...1&d=1663858736

If that extra bright vertical area in the center of the picture is not from the camera
then there may be some timing issue going on with the damper circuit.
But right now I don't think you should do anything about it......

Removal of the 1St Chroma Bandpass Amp Tube V19 Could mean the bars
actually do originate somewhere close. If you look at the Oscilloscope pics
on the schematic of the plate of V19, (Pin 6) you can see a burst group of spikes
for each scan line, This could be your bars if possibly the Burst Osc is not
at the correct frequency, Or this circuit, or any circuit in this video, or Color
processing area is not operating correctly.

You will have to start by checking voltages on each of these tubes......
Put it on a post Pin X, Expected Reading, Actual Reading. Lets All See them.


The Specs .pdf posted a few pages back of one of your meters, and at this
point I'm not sure which, or how many you have, but anyway one of the
meters said it is made to operate within 40 - 4Khz when measuring AC,
I believe..... So be aware the Horiz. circuit is 15Khz, and the color circuit
is some digits above 3Mhz, A question for Cheap-O-Meter accuracy....?
Same for clamp AC Current meters..... Is the clamp picking up 15Khz High
voltage stuff? is it effecting any readings...?

Not sure about the width of the bars makes a big deal not or not. Definitely
could be a decaying "ring" off the Horiz circuit making it's way to the video
or color circuit somehow..... Not ready to put any money on it today...

You have your hands full here..... I'm starting to like the fire idea you floated
a day or two ago.
You know Monday is a holiday.... You might just wanna drag this thing out to
the field behind your house, set it on fire, bring out some Marsh Mellows, a
few hot dogs, and make an afternoon of it.
Post a few pics so we can all celebrate the demise of this thing..... :D



end transmission....


.

As for the voltages I’ll be looking into that and the line in the center if it’s possible it’s a damper I since put a new one in.

Well sams shows 140v on pin 3 of the hots there’s only 100v and the 10k 20 watt resistor is good tried 2 new hots still 100v the 330 resistors are good pulled the 6bk4 cap still 100v and the 385v source on the end of the 10k resistor is there so this flyback may be screwed and it’s new. If I pull both hots the voltage is ok on pin 3. Ok update problem solved I hope the bars are gone don’t know yet if I’ll have video that’s the next post.

If pin 3 of the hot is the screen grid as I suspect then it being low indicates excessive screen current.
Excessive screen current occurs when there isn't enough plate load. If the damper is weak or open the screen should say like that (it will be worse if damper or H out plate lead is open). Or if circuits that normally load the flyback are open or otherwise not drawing sufficient current (even a detuning in the yoke or other resonant circuit could cause this).

The flyback is probably OK...If the flyback had shorted turns the H output screen voltage would skyrocket above rated voltage. Basically the cathode emissions is split between screen and plate (the vast majority to plate). So if the plate takes less of the fixed cathode emission the screen takes up the slack, but if the plate takes more the screen gets less.

If I were you, located where you seem to be, I'd try to find somebody with a 100 MHz scope and a signal generator and make up a couple of bias boxes (9 volt battery and 100K or so pot across it and some clip leads, two separate outfits.)

Have the knowledgeable scope guy visit you and start at the antenna and get the B&W signal to the CRT, with the horizontal and vertical oscillators and outputs completely unplugged. The set should be on a variac set so the B+ is not too high and the filaments not too low.

Next try to get the horizontal (and boost) working, still with a signal getting through with the AGC still running on the bias boxes.

Also remember ... this has been said before but its good to be reminded: never, ever, run the horizontal ourput tube with the plate disconnected or no B+ on it and its screen at normal connection. Its OK to run the screen at something like 20 volts if you can find that somewhere. Usually one just unplugs the horizontal output tube.

I had a recalcitrant horizontal intermittent in my CT-100 and that's what I did ...
using the scope on the Horizontal circuit with the AGC set with a bias box showed that its was the oscillator part that was intermittant. It never identified the bad part so I replaced them all, all resistors included, a second time. That fixed it.
I would never ever have figured all that out without scoping with the AGC fixed.

Found a few problems corrected but the b+ hangs in ok but the 145 190 275 drop off like 20 - 25 volts on each I think it’s a lousy power supply cap the 450v 50uf and possibly the 450v 80uf I keep changing caps then it’s ok then voltage drops again then another cap I’m out of caps.

None of this makes any sense anymore turn it on and as the tubes light the 3 voltages drop and of course the hv is low and I subbed caps made no difference and no tubes are red plating except the hot tube sometimes upon turning on even with the low hv voltages are still very low. This is just crazy already.

Horizontal oscillator 6 150=169 3 150=169 2 1=0 7 10=.8 9 -15=-14 1 .5=.7 where is 169 coming from should be 150.

169 means the tube is not producing the nice spike to drive the Horiz. Output tubes
properly, Especially with the Cathode voltage so Low.

Low HV Probably from Poor Horiz. Output drive to G1's, If it's too high, HV will be low
and Tubes will overheat, and will take your Power Supply Voltages down....

You must have some intermittent poor operation of the Horiz. Osc Circuit.


There are a number of things going on, Osc. Possibly not working right, Causes
H Output to overheat, and brings down PS Voltages.... Get the H. Osc working
right, right frequency, right signal shape, Size, etc. FIRST.


.

Was the yoke plugged in during these measurements?

jr

So, again this is being hamstrung by the lack of an oscilloscope, for the most part. :(

https://www.ebay.com/itm/14475044830...6T4YA&LH_BIN=1

semi OK ones for the price, have a feeling it won't last long b4 someone them all.

Pin 1 of horizontal oscillator has a .5 cap that was 100v but I had put in a .5 630v would this make a noticeable difference. Pin 2 1v but I get 0v and pin 1 .5v I’m getting -7.0v

what cap # is that on the SAMs? :O

C81 but the sams don’t show it in the arrows to identify where it is but it’s there. Another typo

Shown on the picture on page 5.

jr

SAMS shows it to be between r119 - r121 and has a tie to ground with r120.

thus I was a bit confused when you said "Pin 1 of horizontal oscillator has a .5 cap" to me that meant C78, :O

It would be helpful if you gave part numbers from the SAMS to make it more clear :P

that part of the circuit is for sinewave shaping, the larger value volt cap should not matter, BUT value and type WILL.

Yes that was my mistake sorry about that it was not exactly pin 1.

I had put a new flyback in this set whos to say it may be bad in some way or defective I would hate to put the old one back in to see if this helps.

well, until you find someone with an oscilloscope, or are able to get one, you are quite limited.

Username1 mentions that the horizontal oscillator of course is not running correctly and that it don’t seem to have the punch behind the oscillations which makes sense so if there are no resistors bad and voltages are present then the only thing left is caps oscillator coil which checks out fine and flyback the hots were changed as well. Right now I don’t have a scope so I’ll need to push on without it for the moment. And of course if the flyback is good caps make the proper speed and shape of the signal.

There are 2 560pf caps in the yoke what are some symptoms of a bad yoke.

Well I’m not one to give up but it’s altogether and still low hv pulling the 145 190 275 voltages down is it possible there is a problem in the panel that has the g1 control and the red green blue controls. I’m not finding any reason for this voltage to drop and I believe this is affecting the horizontal drive low voltage low or no horizontal drive. It needs 190v and 275v and they drop to far to support the oscillator.

What is a good low esr power supply cap 450v 100uf I have 2 sprague caps in the series circuit and that voltage stays up 385-390v but the other caps that supply 145 190 275 have got to be bad even though my cap checker shows good but in circuit they may be breaking down.

If you have replaced them already, you have virtually nothing to gain by replacing them again at this point, the problem is someplace else.

C3A, C2B, C3B, C2C,
https://www.mouser.com/ProductDetail...nVkrybSw%3D%3D

https://www.mouser.com/ProductDetail...j1prphYw%3D%3D

https://www.mouser.com/ProductDetail...K8MOO7xA%3D%3D

prob replacements.

“low esr” caps are really not the right kind for this area, and hard to find in the values needed, General Purpose Electrolytic Capacitors will do just fine here.

ok I thought low esr caps were better I can’t imagine where this pull is coming from what is it in this set that’s going to pull 3 voltages down I did nothing to this chassis to suggest a major mistake and I can bet it’s the horizontal oscillator alone pulling everything down while still having hv even though it’s low.

a lot of reading about the subject.
https://www.avnet.com/wps/portal/aba...ic-capacitors/

Where it comes into play is higher frequency buck converter type power supplies, but in vintage stuff like this, it would really not help much at all at 60hz line inputs.