Packard Bell Color TV

[old_tv_nut]

Originally Posted by bhegges

old_tv_nut to you question, I don't know, I was thinking that the raster was shifted to the left. During setup it seemed that the raster as a whole was being moved to the left via the purity rings to get an all red screen. But maybe the right edge is just missing the picture and still receiving a black raster.


See the below video where I turned the brightness up and down, the image curves in as the brightness goes up. I can get the right edge of the screen to light up but I don't know is this raster or just light shining through?

• Short Video: https://imgur.com/ZPrGLCY

Just turn the brightness to max and you'll see if that area lights.

Edit: I didn't see the text below the picture at first.
It looks like there is a little bright strip on the right side and then full balck (no raster) (?)
If that is correct, the problem is not horizontal phase but raster shape and centering as you have been saying.

Second edit: Sorry i'm not awake! I looked at the video now and it's obvious the raster goes all the way to the right edge of the tube (and probably beyond) as the whole area lights up.
Once again, you need to go for best purity first and not change that, then see if you get the same effect (light all over the right side when you turn up brightness, but picture pulling to the left.) You may have two problems at once and need to not try fixing one by adjusting the other.

[old_tv_nut]

If the horizontal sync phase is the problem, suspect the phase detector X14 and the components around it.

If your scope is dual-trace, connect one probe to X11 (AGC gating pulse) and the other probe to the video detector output and see if the pulses line up and don't move with respect to each other with changes in video content etc. Make sure your scope is triggering on channel 1 only or channel 2 only.

[old_tv_nut]

also make sure X11 is good

[bhegges]

old_tv_nut, thank you for the troubleshooting ideas, I am way into uncharted territory. I will start with checking components around X14 and X11. I do have a 2 channel scope but will have to pick up a second probe. Stay tuned and thanks again everyone for the advice.

[bhegges]

In looking at replacement parts Sams notes that X14 can be replaced with the following:

• Sylvania ECG 113
• General Electric 6GC1
• International Rectifier DD04

Now in scanning Ebay I see both ECG 113 and ECG 133a, the descriptions states selenium and silicon respectively. Can I assume these are interchangeable and the silicon is likely the better choice?

[old_coot88]

If I had stumbled fresh onto seeing the screen shot in post# 60, the first thought woulda been "borderline-weak H output tube". And the first move would have been the "7 seconds off" test. That is, with the set running, turn it off for about 7 seconds, and back on. If the width is slow to fill back out, the tube may be borderline ('specially if it's been red-plating much). Whereas if the width comes back quick, the tube is obviously good.

It's a 'quick & dirty' little test that can also show up other borderline tubes. E.g., H oscillator, color oscillator, vert output, RF amp.

[Electronic M]

Originally Posted by bhegges

In looking at replacement parts Sams notes that X14 can be replaced with the following:

• Sylvania ECG 113
• General Electric 6GC1
• International Rectifier DD04

Now in scanning Ebay I see both ECG 113 and ECG 133a, the descriptions states selenium and silicon respectively. Can I assume these are interchangeable and the silicon is likely the better choice?

Nowadays shottkey is the best choice followed by silicon...garden variety 1N4007s (you'll need 2) are usable, but shottkeys will work better.

[old_tv_nut]

Originally Posted by old_coot88

If I had stumbled fresh onto seeing the screen shot in post# 60, the first thought woulda been "borderline-weak H output tube". And the first move would have been the "7 seconds off" test. That is, with the set running, turn it off for about 7 seconds, and back on. If the width is slow to fill back out, the tube may be borderline ('specially if it's been red-plating much). Whereas if the width comes back quick, the tube is obviously good.

It's a 'quick & dirty' little test that can also show up other borderline tubes. E.g., H oscillator, color oscillator, vert output, RF amp.

Yes, this could be it.

A circular test pattern like the Indianhead would show the bad horizontal linearity in this case (compression on the extreme right), but you might also be able to detect it with a crosshatch.

[old_tv_nut]

I just looked up 6LQ6 prices online - YIKES. Audiophiles have jacked the market up out of sight.

[bhegges]

So early in my repairs I replaced the horizontal output tube and damper tube with what eBay claimed to be NOS tubes, plus the sellers noted they tested good too (vs just looking NOS). A few weeks ago I picked up spare tubes and swapped these out but did not see any improvement. I don’t have a tube tester so who knows, I could have bought weak tubes.

and yes, silly expensive.

[old_coot88]

We ran into quite a few borderline width cases always on rectangulars, using brand new H.out and damper tubes. Had to finally resort to putting a 82pf, 6KV disc ceramic cap across the damper (cathode to plate). This bumps the width out just a smidjin. Sometimes had to increase to 100 or 120 pf to get 'just enough' overscan.

The mod also has the effect of lowering H.out cathode current slightly (good). But it also reduces HV slightly, requiring bumping the HV adjust up a bit. So there's no 'free lunch'. The usable value for that cap is no higher than 120 pf.

[bhegges]

Assume something like this should hold up to replace the horizontal AFC dual diodes: https://www.mouser.com/ProductDetail...R3IQl24Q%3D%3D

• Schottky Diode
• 3 amp
• 100 volt