1966 GE PortaColor Restoration

[jr_tech]

Excellent! I think that is a very good idea to periodically summarize the steps taken and observations made, especially when the thread starts to get somewhat long, to keep everybody on the same page.

jr

[Electronic M]

Originally Posted by jr_tech

Excellent! I think that is a very good idea to periodically summarize the steps taken and observations made, especially when the thread starts to get somewhat long, to keep everybody on the same page.

jr

The irony being the summary was the last possible post on its page, and in complementing it putting us on the same page the post being complemented is now on the previous page....

[jr_tech]

Unfortunate but true, I am so embarrassed and sorry.



jr

[Dubis7]

Okay, I finally had a chance to do some tests.

I have a video coming. It's a bit long since I tried to document everything I could.

Actually there's two videos, and I may have confirmed my issue. The first has the ringing, some sparking, and shows the "tape artifacts" that I mentioned before. In the second, I removed the HV rectifier, and the sparking etc went away. Obviously some of that will be because there's no power to the tube, but the ringing was definitely around the flyback and that also disappeared when I removed the HV rectifier, so I'm leaning towards that.

One other mystery: Should the HV rectifier tube hold static electricity? I removed it from the tv while wearing gloves (the set was turned off, but I didn't want to risk anything) and put it aside. Later, I went to pick it up without gloves and it sparked when I touched it. Could that be confirmation?

[Dubis7]

https://www.youtube.com/watch?v=dgot...ature=youtu.be

That's the primary overview. Sorry for the length, I was trying to make sure I caught everything.

https://www.youtube.com/watch?v=MQcN...ature=youtu.be

Here's when I removed the HV rectifier.

[old_coot88]

The ringing is probably mechanical vibration of the ferrite core of the flyback. It's usually curable by tightening those two nuts on the big C clamp that goes around the core (not too tight as the core can crack easily).

Your HV rectifier tube is good (if it was weak the raster would 'bloom' and fade out when you turn up the briteness).

The blue arcing when you touch the screwdriver to the glass and top cap of the HV rect is quite normal.

Insufficient height is usually a bad electrolytic coming off the cathode of the vert.output tube (although GE portacolors might not have this cap; other more knowledgable folks will chime in).

[jr_tech]

“Insufficient height is usually a bad electrolytic coming off the cathode of the vert.output tube ”

That would be c-2, which was replaced.... possible error?

jr

[Dubis7]

I checked C2 again. Still not finding an error.

Is there a specific section of C2 I should be looking at?

I did a few measurements by the way. I noticed my HV is hoving around 12KV when it's listed as being between 15 and 18KV. Also, my 670V boost voltage coming off of pin 3 on the flyback is measuring around 650V. Not sure if any of that could be related, but maybe that's a clue?

I tightened the core a bit. Ringing is gone, at least so far.

[Dubis7]

Does anyone have any thoughts on this?

I'm going to try replacing C1 and possibly C2D. I wonder if they didn't get damaged when I installed them incorrectly.

[Electronic M]

Originally Posted by Dubis7

Does anyone have any thoughts on this?

I'm going to try replacing C1 and possibly C2D. I wonder if they didn't get damaged when I installed them incorrectly.

Any lytic that has seen reverse polarity should be immediately round filed and unless you have equipment to test for leakage current at rated voltage.

[Dubis7]

Originally Posted by Electronic M

Any lytic that has seen reverse polarity should be immediately round filed and unless you have equipment to test for leakage current at rated voltage.

Hm. Well now I'm wondering if that's my issue with the height. C2D is definitely a potential culprit.

I had figured that if an Electrolytic didn't explode or smoke, it was fine. Obviously that's not true with the older dried out ones, but these are new. Perhaps I'm wrong?

I've got those parts on order. I'll see what happens when I swap them in. The rest of C2 should be okay.

[user181]

Originally Posted by Dubis7

I had figured that if an Electrolytic didn't explode or smoke, it was fine.

No! That is not a rule-of-thumb.

[Dubis7]

Originally Posted by user181

No! That is not a rule-of-thumb.

Noted. Then I may be on the right track. Recalling that I:

- Attached the line going through R119 and M1 to ground, and attached the negative end of C1 to ground

and that I

- Swapped the polarity of C2D

At the same time. I'm thinking it's very likely that I damaged C2D at that time, which could explain my height issue.

Parts are on order. I'll see what changes once I swap everything in.

[Dubis7]

Still waiting on C2D to come in. I was doing some work in the power supply tonight.

I've got a new issue. It's my fault. I won't get too into it, I did something stupid trying to check a component and learned my lesson. Blew out R119, M1, C1, and X1. X2 still looks okay, but X1 is now measuring 0 ohms regardless of the polarity. The set blows M1 immediately upon power up. I disconnected the 270V line between C2A and L34 and it still blows, so I know the problem is in the voltage doubler circuit with X1 and X2.

R119, M1, and C1 are now replaced. R119 is now 3.9 ohm 10 watt, and M1 is a 2.5A 250V fast blow fuse. I also took the opportunity to install M2 as it's listed in the schematic, so I'll have that extra protection.

I'm not sure what diode to get to replace X1. Any suggestions? I'm trying to decide if I should go ahead and replace C103 while I'm at it.

[Dubis7]

Would this replace X1?

https://www.ebay.com/itm/5pcs-1N2071...UAAOxynhFRBp5P