1970s Zenith Console - Troubleshooting

[zeno]

The pix is not up to how they looked. I think the CRT is a little weak.
That will make it hard to set up. Cant tell for sure from up here in NH. !

Check a few things.
Boost, 1K resistor on focus pin if CRT, be sure instant on
is working. Also for laffs check the CRT date codes & EIA ## to
see if its OEM. Check diodes on convergence panel.

73 Zeno
LFOD !

[ThePlague]

Originally Posted by zeno

The pix is not up to how they looked. I think the CRT is a little weak.
That will make it hard to set up. Cant tell for sure from up here in NH. !

Check a few things.
Boost, 1K resistor on focus pin if CRT, be sure instant on
is working. Also for laffs check the CRT date codes & EIA ## to
see if its OEM. Check diodes on convergence panel.

73 Zeno
LFOD !

Too bad I didn't get this far on it while I was still in CT last year!
I am not sure what you mean by "Boost" but I checked the resistors out when I had the socket apart, all good there. Instant on is working.

I attempted to re-do my purity and I think that helped a bit. I re-seated all of the Semis. The 221-46 Semi on the Chroma Duramodule had two legs fall apart. Thankfully I had a NOS one from another Duramodule and that did the trick.

The CRT is OEM and an AG125VB0P22 (if I read the faded label right) with a date code of 4-13 punched out. Early on I complained of faint letterbox burn in. It never came across in the pictures, but it is certainly there. It wouldn't surprise me that this is a high mileage set. The red gun certainly seems weaker/more orange in comparison to blue and green when turning each color down.

Below are my best shots so far. I'm going to order some convergence strips for the left side. But other than that this may be where the set sits for awhile as I am bit burnt on it.

Is it feasible to source an Chromacolor tube for this unit? I have heard of people who hoard them.

[ThePlague]

I'm 95% I am dealing with a weak CRT. Hopefully I can find someone with a tester near Denver area.

Would replacing the HV tripler help at all? If that HV divider was destroyed its a possibility the tripler took some damage. I am not sure what the symptoms of too low of HV would be though.

[zeno]

Yup thats the original jug. Almost 50 yrs & still quite usable.
Make a list for subs. CC2 sets are real common & probably use
the same one. Just be sure its a 30 Kv tube. Hybrids will
have 25 Kv so no go. I think you have a 25VDQP22
check the Sams.
The set up looks good. Last test is turn off the lights & turn everything down low. If the pix gets sharper its CRT

Zeno

[ThePlague]

I've been checking possible replacement tubes off and on lately. I have a line on a NOS 25VAQP22, but I am not sure if it is a possible replacement.

I know the following information.

I have a 25VBQP22 in the set (looked like a D in the picture, confirmed with the Sams).
Per a 1976 Zenith interchangeability guide, the 25VAQP22 and 25VBQP22 (also equivalent to a 25VBNP22) are both replaceable by a 25VCNP22.

Per a 1982 Zenith guide, the 25VAQP22 is listed as a direct replacement for the 25VBNP22.

I am fairly confident that the 25VAQP22 will replace the 25VBQP22 based on that chain of equivalences, but I was wondering if anyone has information regarding this?

[BeamT]

I am at the same place with my 25DC56 restoration. My set has the original Zenith 25VBQP22 CRT. I believe my set is low hour but it was plugged in it's entire life, prior to me purchasing it on FB last year. My CRT tests good on a Sencore CR70 but does not test well with the life test. The red gun is the weakest of the 3 and no matter how I set it up, it does not want to track well. The focus peaks but isn't very good. It looks much better in low light. I did not try to rejuvenate/restore because it is still watchable. I'm hoping to get my set to a better level.

I have several generations of Zenith, Video Display, and Sylvania CRT guides and came to the same conclusion you did that the 25VAQP22 was a substitute. I was able to find a VDC 25VAQP22 and plan to install it over the holiday weekend and will let you know. Is the tube you are considering NOS or rebuilt?

I haven't been able to understand how a rebuilt VDC 25VAQ compares to the original Zenith CRT? Black Matrix? How did the rebuilders, Zenith, Sylvania, RCA, VDC, compare with each other?

[zeno]

Zeniths solid states with DC, EC FC & maybe CC chassii are
instant on. Be sure its working, when turned on cold it should come
right up in a few seconds.
All flat chassii & early CC2 uprights MUST have new 22-5001 HV
safety caps IF they are white. Orange ones are OK.
Late EC & FC chassii uses the 4 lead cap. Be sure it is orange.
Also be sure you use the right one ! There are at least 3 others for different
Chassii such as 13", EFL CRT's , System 3 etc. Most uprights
used the 800-860 kit BUT be sure !

enuf fer now
73 Zeno
LFOD !

[ThePlague]

Originally Posted by BeamT

I am at the same place with my 25DC56 restoration. My set has the original Zenith 25VBQP22 CRT. I believe my set is low hour but it was plugged in it's entire life, prior to me purchasing it on FB last year. My CRT tests good on a Sencore CR70 but does not test well with the life test. The red gun is the weakest of the 3 and no matter how I set it up, it does not want to track well. The focus peaks but isn't very good. It looks much better in low light. I did not try to rejuvenate/restore because it is still watchable. I'm hoping to get my set to a better level.

I have several generations of Zenith, Video Display, and Sylvania CRT guides and came to the same conclusion you did that the 25VAQP22 was a substitute. I was able to find a VDC 25VAQP22 and plan to install it over the holiday weekend and will let you know. Is the tube you are considering NOS or rebuilt?

I haven't been able to understand how a rebuilt VDC 25VAQ compares to the original Zenith CRT? Black Matrix? How did the rebuilders, Zenith, Sylvania, RCA, VDC, compare with each other?

I look forward to hearing back from your efforts! I was able to get a NOS tube, but am currently working the shipping logistics part of it.

I currently have the same issues as well, but have done all of the replacements mentioned by Zeno. (Set comes on quickly). Thanks again Zeno and all who chimed in for helping getting my set to at least the "usable" level it is at.