Zenith Projector 1985

[mbates14]

well if you got fungus growing in those tubes, all power to ya trying to change it. youll have to cut the CRT away from the manafold to even clean it out. it has a drain screw, but you still have to wash out the CRT.

[JesusJones]

Thank you every one.

And yes after I found out this projector was made in the first year Zenith began making these. I knew it would not be very great, but I thought it would just be fun to toy with. And if it did work half as well as I thought for 10$ it woulda been a steal.

I'm gonna check for mold. Mold would be a god send. (easy inexpensive fix)

Mbates14 You mentioned the splitter assembly. What part is this more specifically?

And I have seen "One" schematic for this projector, but you had to buy it. Other than that I have looked and looked(You probably have to) And it's impossible to find.
This is the page http://www.analogalley.com/m_zenith.htm
I didn't wanna pay for it. Just so i could be sent the wrong one.

And the HV goes to a splitter. Here at the splitter are some controls. (For each tube.)
From playing with them I have noticed they make the color brighter or dimmer.
There is Low medium and High jumper and then a vari pot to fine tune.
Blue and Red were set to medium. And green was set at high when I opened it.
This leads me to beleive the tube was most likely cranked up higher and higher till death(Shucks) (Or maybe there was just more and more mold!)
Also upon starting the unit during the nite I Noticed HV arcing to the frame.It was not intense and stopped after a second or two. But maybe this is a sign of something?

Oh and I got the picture right side up by changing the yoke pin connections. Now it's rightside up. No miracles there

Rudy

[mbates14]

Well if you look down the lense while on, or taking a flashlight to it, it will be pretty evident.

I would take the 4 screws out of the lense from the manafold, and take a look that way. there we ill be a "gell like" substance on the face of the CRT glass manafold. its nothing to worry about, just a moisture sealant.


this way you can inspect the CRTs phosphor condition, along wiht fungus, etc etc.

if there is extreme fungus, its not a godsend. its harder than you think. you have to cut away all the silicon between the CRT and manafold to change the fluid. as IT IS all in one CRT, meant to be replaced as a whole assembly.

I dont even use mine anymore, it worked when i last put it up, I wanted to find something different, but i never could around my part of the globe. hehe. (im in cincinatti area).

and, oh yea. if you have to take the CRT apart, careful not to loose the plastic seats that fit between the glass and metal manafold, it holds the CRT a certain position away from the face of the glass.

[JesusJones]

Yea I'm in winnipeg Canada. Things here are hard to find and generally not cheap.
Garage sales are always the best bet for me.

You mentioned the splitter circuit if the gel was not full of mold?

The esr meter tests capacitor leakage or what? I looked it up only briefly. I might go buy one right now if it's that good

The schematic you want on the page has PV800P as the service #

And I don't think it's mold. Every crt through the lense looks the same. A nice grey colour. With red showing the most wear actually.

[mbates14]

yea but if your HV is staying up, your splitter is fine.

[mbates14]

I honestly think you need to get to all your capacitors.

Dick Smith ESR meter. you can get the kit, or buy the meter outright.

[JesusJones]

Ok I bought the new blue one. Looks kinda shabby compared to the black one but that's ok.

I think I paid only 70 or 80$ for it. Sound right to you?

[mbates14]

yea thats around that price.

[rcaman]

those tubes did not have coolant for cooling. there is a gel pad between the crt face and lens. thats not your problem.

[mbates14]

yes it does. I can prove that to you.

there is a gel pad between the glass and lense, but there is fluid between the face of CRT and glass. Crack the glass by accident one time, youll see.

[bgadow]

I dug through my Zenith service manuals last night. They are a real mess, I need to organize them. I found a number of projector manuals from the 80s but I don't know if any of them are right. There are several dated in the later 80s and one undated one that looks pretty early.

[JesusJones]

PV800P
It was also called a monitor
And the year was 85. And there were two inputs audio video and one output for video.

Also the 810 and 820 models were the same as the 800. Just different casing

If that at all helps narrowing down a schemtic or something close

[JesusJones]

Curt Palme is a Hero.....He said he has a nice new green tube for me that hes willing to send over for a very reasonable price.
I wanna take it...think I should?
Mbates? I trust your judgement on this. You say this projector is reliable. And I am going to test the electrolytics and replace them if necessary? You think tubes would be worth it?

Theres also the issue about the gel that is apparently not reusable. But you said you've done something like this? Is it doable?

[andy]

...

[JesusJones]

Ya Know for 10$ I wasn't expecting it to be HDTV that could project on the side of a building. I knew it would be like a normal CRT tv at best.

And just from watching the red on the wall completely unadjusted and a lit room. I have no doubt this projector will suit my needs.(Play nintendo haha)

And I have a question for you Mbates14.
The power supply on your unit. Is it normally quiet?
Mine is making a ticking/buzzing sound. And also after a short run time the large resistors will already have considerable heat on them. Could a bad cap in the power supply cause any type of noises?

And would a weak power supply maybe explain why the tubes seem weak.

I've thought it over and no one could have possibly watched this unit till the green was as weak as it is showing right now. Maybe they put it aside due to failure of something else? Like the power supply?


Woah hoah hoah

After remembering the unit was mounted upside down. Suddenly all these brown burn looking marks made sense. On the raster regulator there are 9 vari pots.
The 3 on the bottom were seized. And under each one it was charred brown. Before this made no sense to me. These burns appeared to start from nowhere and end nowhere so I disregarded them. But now it makes sense. Because the heat and smoke was traveling the opposite way I thought. So I have some cooked pots I think. Mbates14 is there were you had to rewind the pots? by chance


Actually(after another quick check) this vari pot idea makes way to much sense. Of the three that are cooked, RED(my only well working color) can still turn.
Blue and Green Vari pots for this adjustment were seized and the plastic knobs snapped off.(With little effort) This finding just makes too much sense.
Anybody else have thoughts?
Thanks for your time
Rudy