CurtPalme.com Home Theater Forum

**Curt Palme** · Posted: Sat Jan 03, 2015 2:39 am Post subject: Bizarro Marquee problem

Here's one that's new to me.. and tim was no help today either. Mr. Green

So it's weird for sure. I installed a Marquee 8110 a few years ago at the local university pub. They run it 14 hours a day, and I replaced the set about 18 months ago, as they'd worn the original one out. This set is still in OK shape, although showing tube wear.

They called before Christmas saying the set was dead, and clicking, with the red LVPS light on at the CLM. I take a new 2008 power supply (tested) with me, and replace it. Set fires up, fixed, right? Nope, 48 hours later, it's dead again. 2 more trips with HDM, neck board, etc. and the damn thing fires up solid as a rock, then dies again 24-48 hours later. Eff me!

So on the last trip I found that if I disconnect the convergence ribbon cable, the pix comes back. So finally today I got smart. I took my buddy with me to pull the set down, but also take with me a tested rear heat sink assembly. I put it into the set, same LVPS overload clicking. I leave the set live, yank off the convergence ribbon cable to the motherboard, and it instantly fires up. Power down, connect again, fire up with the convergence yoke connectors to the tubes off.. still clicking.

the set is now in the back of my truck, and I'll dive into it tomorrow, but I'll be damned if I know what it is. Since the set comes back to life once in a while, I don't think it's a component failure. My guess, as is Tim's, is that maybe there's a bad connection somewhere on the power supply rails going to the convergence board, and an imbalance between the +/- voltages on the rails is causing LVPS overload? I did also change out the convergence ribbon cable today, same problem.

I'll post once I fix it, but I ain't making a dime on this stupid repair due to the number of trips across town!

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

Might be something shorting on the MB, maybe a screw came loose etc.

Athanasios

dvh99 · Joined: 25 Dec 2009 Posts: 2158 Location: nederland

tube problem most likely then.

**Curt Palme** · Posted: Sat Jan 03, 2015 5:07 pm Post subject:

How can a tube shut the set down with an LVPS failure error light. I totally disagree...

barclay66 · Posted: Sat Jan 03, 2015 5:53 pm Post subject:

Hi,

Maybe there's too much current draw on one of the supply lines that the convergence amp is connected to. By disconnecting it, the draw drops just enough for bringing the LVPS back from the overcurrent protection state. The CVA uses +/-24V and +/-15. In addition it routes power to the stig amp too. Maybe the culprit is somewhere else and creates the problem on one of the supply lines. I would check the modules that share them with the CVA and check the LVPS LEDs too...

Regards,
barclay66

HK-Steve · Posted: Sun Jan 04, 2015 10:32 am Post subject:

Maybe a crack in the LVPS connector in the chassis........

draganm · Joined: 08 Mar 2006 Posts: 8990 Location: Colorado

Motherboard or back-plane, or to be specific, the socketed connectors that join the 2. Pull the mobo out and see if there's any burnt looking sections to the Molex connecotrs.

Had a guy with intermittent HDM problems, turned out to be the connector on the Mobo.

Jeremy112 · Joined: 28 Sep 2006 Posts: 2649 Location: Fond du Lac, WI

I'd just swap the projector out with a different one, and part that one out - given the amount of them you have anyway Razz

That's what I do when I get a projector in for repair that's difficult - I just offer to swap it with an equivalent working one, then I don't have to worry about the customer getting antsy Smile

I know, this post was no help Razz

**Curt Palme** · Posted: Sun Jan 04, 2015 8:40 pm Post subject:

I already did that with the last one. It was easier to sell them a retubed one rather than pulling theirs down, bringing it across town, etc. It will be on the bench tomorrow, right now I'm working on MY theater for an effing change!

About to flip breakers on the two new 15 amp circuits.... if you don't hear from me again, don't worry, the 120VAC defibrillator didn't work!

draganm · Joined: 08 Mar 2006 Posts: 8990 Location: Colorado

**Curt Palme** · Posted: Tue Jan 06, 2015 7:10 pm Post subject:

It's a good idea, but I'd have to bring their set in, swap tubes, etc. Would have taken the same amount of time as fixing theirs, which I now have.

Everyone was wrong including me. Was a bad CLM! Not sure why, but my guess is that maybe intermittently it would glitch, maxing out some comvergence parameters. Put in a different CLM, it fired right up. Put the old CLM back in, and the LVPS failure light came back. NOt even going to try to repair their CLM, short of trying a reset, to see if that clears the fault condition. Will run the set overnight, and then take it back tomorrow.

No way would I have been able to diagnose this in the field!

Before I got to the CLM, I pulled the CRT socket connectors, focus and HDM board along with the VIM. Same problem. Before I pulled tubes and the motherboard, I decided to change the CLM, and that did it.

One for the notebook, that's for sure.