CurtPalme.com Home Theater Forum

[ScubaStan]

Hello!

I recently acquired an NEC 9PG in fairly good condition. With a little over 2000 hours on the set's counter, the blue and green tubes are at a 7.5 of 10, with the red tube having no noticeable wear.

After getting it home, I powered it on and reset all the image adjustments to their neutral point. I had it running off the video input from a VCR, then hooked up my computer and ran it at 1280x1024 while I started making adjustments. The whole while, the set ran pretty much fine, aside from not wanting to sync to 800x600, but all other resolutions above or below.

It started giving me trouble after I moved it from a coffee table onto an older TV stand. I powered it up and pulled up an image from an NTSC video source, then tried to switch to my PS2 on the RGB input, running at 480i with sync on green. The projector would not lock to the signal, giving me a scrambled image, and made an odd buzzing sound. I disconnected it and went back to the video input. When I pulled that back up, the image seemed to 'shrink' for a second before cutting out completely. No raster on the tubes at all, no OSD, nothing. The two digit display on the rear was flashing an "F3" error, pointing to the point convergence board. I removed that, and still nothing. I disconnected the convergence board and the unit powered back on, of only for a moment to give me the same 'shrinking image' problem. Then, the image completely defocused and powered back off, with no errors indicated on the display.

I left it overnight and went to work the following morning. After coming back, i powered the unit back on and it seemed to be functioning again. I plugged the C-board back in, and things were still good. Reinserting the point convergence board still gave me the "F3" error, but removing it restored functionality again. I could make regular adjustments and use the projector like normal again, until I tried to use the RGB input, this time with a 1024x768 signal from my computer. The image came up, without the 'shrinking' problem this time, for just a second, with the message "incompatible input" or something like that overlaid on top. The image was displayed properly, it looked sharp and in focus. After a few seconds, the image defocused again, and the tubes went blank. I cannot get any image to display on the set at this point.

Is it possible that I may have loosened some vital connector when I moved it? The set was running for a good ~4 hours the night before I moved it, so i find it odd that something would just up and fail right after, plus the fact that it was somewhat functional after leaving it for a day was odd. I re-seated the system and wave boards to no luck, leaving out the point board altogether. There are no errors on the display, and the H and V failure lights are not lit. Is there anything else I can check? I'm fairly skilled with electronics and component-level replacement, so I can work on the boards if need be, it's just diagnosing the problem that is the issue. I'm already planning on disassembling the set the next day I have off and cleaning all the contacts, just to see if that may be the problem.



Also, I got a free Zenith Pro2000/Toshiba P7300U out of this deal too, though I can't seem to power it on without a remote. Not much seems to be known about the set. Anyone have any direction as to how I could get a remote, or codes for a universal?


Thanks for any advice!

[ScubaStan]

Another update: After tinkering with it some more, I got it to come on again. I would get a good raster on the red tube, and a very dim raster on the other two, before it switching back to the "Incompatible input", or whatever message for a second, before defocusing and shutting down. After another attempt to power it up, after the HV initializes, I noticed a "click" coming from the HV area that it didn't make when I got an image. Is this possibly an HV protection shutdown of some sort? Could the flyback or any associated parts going out cause this? Thanks.

[Curt Palme]

Welcome! tyhe PG was a really good set in the day, but if you do a search on the forum here, you'll find a zillion posts about leaking capacitors on almost every board in the PG. The electrolyte eats through PC board traces, and I stopped supporting the Pg set about 5 years ago and threw out all the parts due to that problem.

If you want to get this set going, you really have to pull all the caps and replace them, which to me isn't worth doing, but you seem to have a grasp on electronics, so you might want to attack that. The Zenith 2000 is a rare beast, I've never seen one, but I think you're right, you'll need the remote..

[Curt Palme]

Welcome! tyhe PG was a really good set in the day, but if you do a search on the forum here, you'll find a zillion posts about leaking capacitors on almost every board in the PG. The electrolyte eats through PC board traces, and I stopped supporting the Pg set about 5 years ago and threw out all the parts due to that problem.

If you want to get this set going, you really have to pull all the caps and replace them, which to me isn't worth doing, but you seem to have a grasp on electronics, so you might want to attack that. The Zenith 2000 is a rare beast, I've never seen one, but I think you're right, you'll need the remote..

[gjaky]

As for the Toshiba P7300 try to search in google, I think there are universal remote control codes for that unit. In theory it should be a better machine than the 9PG.

[ScubaStan]

Thanks for the advice guys. I actually think I found the problem, when I moved the projector onto the stand, it didn't have its standoff feet on it, and the PJ was sitting on the bottom plate of the chassis. Once I put some spacers under it, all of my problems seemed to fix themselves. As far as the caps go, I've looked over all the boards that I can get to, and everything seems to be in good shape. No bulging caps, leakage, etc. I'll be taking a closer look tonight though.

I'd like to get this set running and keep it for a while, as I'm not in the position to upgrade any time soon, though id like to get a 9' set eventually. Any advice on what would be good nowadays for that?

As far as the Zenith goes, I haven't really looked at it that much yet, but it's in pretty rough shape. The blue tube is maybe a 6, haven't pulled the lenses for the others yet, and there is visible rust on some metal sections of the chassis. The lenses are also in pretty bad shape for both of them, with internal dust, scratches on the AG coating and what looks like the start of fungus in a few of them.

[gjaky]

The cap leakage on the PGs are not very aparent, until you don't want to unsolder a cap, then you'll immediately smell the distinct leaking cap fart...

As for the Toshiba: it is unfortunate that it has bad lenses since it should have HD145 lenses which is considered superior to the HD-6C-ML lenses that can be found on the PG.

[ScubaStan]

Well, it seems to be giving me troubles again. I'll have to start taking it apart and see if i can find anything obvious. I don't suppose there is any 'go to' thing to try first? I've got the diagnostic manual but it seems like a lot of steps require a scope, which I don't currently have. Would really like to have this one running, since i'm probably not going to be getting any other PJ's soon. This is the only listing on the local craigslist for over a year now.

As for the Toshiba, no luck on remote codes, though i'll keep trying.

EDIT: Maybe it's just my ignorance again, but it seems like you have to actually have something connected to the PJ for it to power up properly? I had a BNC-RCA adapter in the video socket so maybe it was trying to sync to something that wasn't there. Works fine again, lol. Also, the unit has just under 100 hours, not 2000! I guess reading upside down and backwards is tough sometimes. Plus, I found some codes for the toshiba, just have to get a JP1 Programmable remote and cable to use them, it seems.

[Zolzar]

Bad capacitors may be obvious to the naked eye and then again they may not be. I picked up a 10PG about four years ago. It did not run right when I got it. It was very unstable and just wouldn't work right. The bottom line with he PJ was that I had to replace ALL of the capacitors on the unit. Probably around 300 or so. After carefully competing the process I have had a rock solid and reliable NEC PG series projector. I got the PJ with less than 1k hours for $0!!! Do yourself a favor and invest in replacing all of the capacitors. It's pretty much your only solution with these NEC units. Forget the service manual adjustments that require a scope. I have a scope and would absolutely never attempt any of the service adjustments. The manuals from NEC are notoriously poorly written. Plenty of people have attempted some of the adjustments only to be screwed. The only "deep" settings you should be attempting is your drive setting in the menu for color balance and grey scale and the astir adjustments. The scope is not necessary at all.

[Zolzar]

https://www.curtpalme.com/forum_archived/viewtopic.php@t=32703.html

[ScubaStan]

Ehh, I guess its some caps or somesuch. Intermittent issues showed up again. Anyone know how I can get a parts list together?

[ScubaStan]

[deronmoped]

Don't use the point board. It's not needed if you set up the PJ correctly.