Zenith Projector 1985 - Page 6 - Videokarma.org TV - Video

JesusJones · #76 10-28-2008, 01:46 PM

Today my ESR meter came. After spending 2 hours putting it together I was very happy to see it work properly when I turned it on

So I got right to work on the power supply.

All electrolytics are fine.(Suprisingly...Gonna switch em anyways)
The only capacitor which did nothing on the esr meter. Was that safety cap I mentioned before.

It is green and larger. Looks like a dipped radial cap. You guys know.

The only thing it says is:
Crit Safety Comp
(s) 22-7672-10 8441

I doubt that means anything other than a model # but maybe it helps.
Any idea as to what one of these safety caps would be rated .1 uf, .01uf 1000volts?

Thanks Rudy

mbates14 · #77 10-28-2008, 01:55 PM

you sure your reading that meter right? i dont think they are all going to be perfect. and it would take longer than a couple hours to go through all the electrolytics in that set. hehe.

radiotvnut · #78 10-28-2008, 01:58 PM

I don't think you have to worry about that green safety cap. They were used in most '80's Zenith TV's and I've never seen one fail. And, I've worked on many '80's Zenith's.

JesusJones · #79 10-28-2008, 02:02 PM

haha Oh no not all of them.

I went at the power supply first because I know there was that strange sound in there.

And I dono if i'm just getting used to it or what. But I could be wrong I'll go double check again soon.

But the safety cap just showed an open short. No connection at all. Unless its really small. Like .02 or smaller. It should say something.

JesusJones · #80 10-28-2008, 02:11 PM

haha Oh no not all of them.

I went at the power supply first because I know there was that strange sound in there.

And I dono if i'm just getting used to it or what. But I could be wrong I'll go double check again soon.

But the safety cap just showed an open short. No connection at all. Unless its really small. Like .02 or smaller. It should say something.

And I checked capacitors again IN ONLY THE POWER SUPPLY
They all check in .25 and smaller Which is correct I think. And none vary greatley from the other similar values. What would a dead cap come in at...Say 470 uf?

Sorry about the double post
Damned Internet!

radiotvnut · #81 10-28-2008, 02:58 PM

That safety cap is probably rated in the .0039 to .0068 range.

JesusJones · #82 10-28-2008, 06:31 PM

Ok I will leave it alone then.

And as I was pulling boards and checking them I noticed a board that had two cables switched and in the wrong spots. The letters on the connecters clearly did not match the baords. Should I look further into this? Try switching it?

I also followed the wires. The connecters are connected to the board with sharpness, brightness, balck level and all that stuff.(AT this board they are in the correctly labelled spots) Then they go to the board at the right side of the projector facing the lenses. This board then goes to the video boards on the crt necks. Mbates you should know what this is. Any advice?

Thanks
Rudy

JesusJones · #83 10-29-2008, 12:08 PM

Mbates does your projector have a 3 prong plug or two?? The noise in the power supply gets quieter when I touch the ground/frame.

Also the noise got quieter after changing some caps on another baord. I think I"m getting used to the ESR meter. And I love not having to take things out to give a good test.

So I just wanna throw this out there again.
The green tube in my mind is weak/dead
When I originally got the unit the green focus/HV was CRANKED up.
I have tried switching the CRT neck boards, so that the green tube gets all red info and the red gets all green info.

The red still worked and the green did not change.

I mentioned before a way to try and rejeuv this tube using a lightbulb and mains voltage.Any thoughts on this?

The only thing that I have not tried changing for this tube is the HV line.
All three CRTs have HV lines Going to what I call the HV splitter. They are easy to pull and switch. Should I try switching these around??

Any one have any suggestions? Should I try a rejeuv or something like that? Any thoughts?

Thanks for your time
Rudy

P.S. I noticed in the HV transformer there was a cap type deally. It screwed off and inside there was nothing. I shined a light in and noticed a spring at the bottom. The only thing I think this could be for, was a fuse. And there definatley wasn't one inside. Any one know what this might be?

JesusJones · #84 10-31-2008, 01:02 AM

Happy nBirthday to me"

Happy Birthday to me

HAPPY Birthday too meee

Happy Birthday to me!

mbates14 · #85 10-31-2008, 10:21 PM

yea those are quick connects for the HV wires and stuff. My unit is a 3-prong power plug.

JesusJones · #86 11-03-2008, 12:45 PM

Alright so I've tried everything to get that green tube shining brightly(HV line switching, CRT neck board switching) But nothing helps.

So I'm going to try leaving the set running for a couple hours.
I've heard this sometimes brings a tube back...?

Also, Mbates14, does the ground from your plug go to ground(chassis)? Or to the power supply circuit board?? (if you know off hand)

Thanks
Rudy

mbates14 · #87 11-03-2008, 05:48 PM

I have to dig it out. its burried under boxes and other crap for the last 3 years.

JesusJones · #88 11-05-2008, 01:16 PM

Alright well I have changed just about every cap on this set that has a strange/high esr reading. The power supply has also been totally recapped.

The noise in the power supply still exists. I've noticed it only starts up when you apply an actual video signal to the projector. Then the power supply starts it's buzzing.

I've also noticed that the power supply shuts up when you put your hand on the frame. I've considered putting a ground wire to the frame. Good idea??

Theres one more cap I am going to change. It's a small one but the only other one I can remember giving any sort of bad reading. After this I will run the set for 3 hours.
The only reason I havn't already is because of the power supply noise and how quickly some of those resistors in the power supply get HOT.

If anyone could tell me there thoughts here. Should I put a Ground to the frame? Is the power supply acting more or less normal? Should I go for the 3 hour test?

Any thoughts would be much appreciated. Or else I"m just gonna continue on with my plans and hopefully not destroy the thing..

If you think it's a good idea wish me luck
Thanks
Rudy

mbates14 · #89 11-05-2008, 07:27 PM

ground on the frame is typically a good idea anyway.

JesusJones · #90 11-06-2008, 11:51 AM

Thanks Mbates

After some studying I went ahead and put in a new chord with ground and attached the ground to the power supply.

It was quieter but didn't work any better.

I let the set run for a while. And the green didn't brighten up any by the end. Maybe just slightly but enough to make a veiwable difference.

So I wanna try and give the green some new life. Just to see if it works...have some fun.

I have 3 ideas. But do not know witch is the best way to go about it.

Idea #1
Bump up the heater voltage temporarily untill the tube begins to work better. Then return it to normal.

Idea #2
With the heater ON. Charge up a Capacitor. And zap g2 and cathode pins.
(1 uf cap starting with about 100 volts)

Idea #3
With heaters ON. Use a light bulb to do the same thing as the capacitor.

Tell me what you think works best. And I will try it out. I have nothin to lose at this point.
Thanks for your time.
Rudy