CurtPalme.com Home Theater Forum

Ficus · Joined: 26 Dec 2015 Posts: 3

Hi there,

I recently purchased a used Sony VPH-1272Q with around 3500 hours on the tubes. The previous owner had taken this particular projector down a few years ago to upgrade, and it lay unused. This is my first foray into CRT projectors and it is as much a project piece as a way to get a pretty good large image for relatively cheap (and having seen an uncalibrated SD image look pretty darn good, excited to get tinkering and see what it can manage). I have yet to do a proper set up, but have spent a couple of hours familiarizing myself with the controls (resetting to factory settings, beginning to adjust registration, etc.). I'll save the proper setup until I have it in position.

So far, I have tested it with a few different sources: a blu-ray player playing DVD through S-Video, a DVD player playing DVD through S-Video, and my computer (using a homemade VGA-->RGBHV cable).

At some point during the testing and switching inputs and trying different resolutions to feed from my computer, the projector's image started flickering on and off. I assumed I was giving it a bad input so shut it down and started up with no input. The issue persisted, so I shut it down and plugged it into a different outlet. On restarting the PJ, the problem seemed to go away, but has now come back with a vengeance. Now, regardless of where it is plugged in (including a power conditioner) and with no inputs connected, the red and green tubes flicker on the white 'warm-up' screen. When I click through to the empty inputs and display test patterns, the image is alright until I display the full white screen test pattern, at which point both the red and green tubes flicker. If I shut either the green or red tubes off (using the cut-off buttons), the image stabilizes almost completely, but both resume flickering when they are on simultaneously. EDIT: there does not seem to be an error code.

So my questions are these:

1. Troubleshooting procedures? Theories as to what might cause this problem? What are some standard PJ cleaning procedures for checking / cleaning all connections on all the PC boards? I am fairly proficient at cleaning contacts in older tube amps, but don't know where to begin with this style of PC board.

2. Could I have damaged the PJ in some way through turning on/off frequently or plugging and unplugging BNCs while signal and PJ are on? Shocked

Thanks in advance for any help and excited to join your ranks with my CRT PJ!
Ficus

barcodude · Joined: 14 Jun 2014 Posts: 169 Location: The Netherlands

try to contact the original owner if he or she had the same problem?

**Curt Palme** · Posted: Sun Dec 27, 2015 3:03 pm Post subject:

The most common problem is bad connections on the CA(g) board. There`s a gray ribbon cable at the back of the CA(G) board that can oxidize. Pûll that out and reinsert it a couple of times, and see if it doesn`t go away.

http://www.curtpalme.com/Sony125x_Layout5.shtm

Ficus · Joined: 26 Dec 2015 Posts: 3

OK, thanks Curt. Will try that along with reseating boards / connections throughout the PJ. As a side note, is there a list of acronyms and their meanings somewhere on this site / the internet? I have managed to figure out a few of the obvious ones, but would be nice to know what CA boards, BB boards, DE boards, etc. refer to and the service manual assumes a fair amount of prior knowledge! Shocked

And good idea -- will contact previous owners.

**Curt Palme** · Posted: Sun Dec 27, 2015 9:19 pm Post subject:

Read the service manual. THe board designation is more or less random, although there are some groupings within them.

Ficus · Joined: 26 Dec 2015 Posts: 3

UPDATE: Reseated PC boards and cleaned connections (with contact cleaner) for gray ribbon cable on CA board as well as every other connection I could reach without too much in the way of disassembly. Wow! These machines are definitely meant to be serviced. I appreciate the car hood style hinge. Video and RGBHV signals are immediately cleaner and more stable.

Thank you for the advice and helpful site.