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Discussion Starter · #1 ·
OK, so today I finally got around to taking down my 8000 and installing my fully tested, working, freshly retubed 9500LC.



I get done, apply power....and it doesn't power up.


When the LVPS should power up, about a second after you press the power button, the red LVPS fail indicator lights and stays lit until you unplug the projector.


I swapped a spare good LVPS in, and got the same results.


Watching the LEDs on the face of the LVPS unit, the third one nearest the input power connector will flash briefly about once a second when you attempt to run the unit.


Clearly, something is overloading the LVPS.


But what's really going on here?


This unit has been gone over with a fine tooth comb as I totally rebuilt it and

cleaned everything. I've taken extreme care to not let anything get dropped into it. It's been treated with total respect even as I've done EVERYTHING to it.


And it ran FINE this morning before inverting it and mounting it on the ceiling.


What's a most probable cause? LVPS fails on load after inverting the unit.


Not only have I double checked all the connections, I've reverted them to normal

scan as well, which is how it was set up for test.


I'm starting to pull boards out to find the load.


Any ideas?



CJ
 

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Discussion Starter · #2 ·
Further info....I noted that on the LVPS board, below the status indicators, the one that flashes is labelled -24 volts.


So the fault is presumably on the -24 volt line.


CJ
 

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Discussion Starter · #4 ·
I'm working on it. Trouble is, I'm not ABOUT to try to drop the PJ all by myself. My help has gone for the week.


I've made some progress, but no definitive answer yet.


If I have to, I'll strip the chassis down all the way, in place on the roof.


CJ
 

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Hi CJ,

Quote:
Originally Posted by cmjohnson
Further info....I noted that on the LVPS board, below the status indicators, the one that flashes is labelled -24 volts.


So the fault is presumably on the -24 volt line.


CJ
Well, I'm not sure I would conclude that that is the reason. However, IF it really is the

-24V line it should be easy to test. The -24V powers the belly fans, the FCM and the

CVA. It's one of the lesser used rails :D :D


Regards,

Reinhard
 

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CJ


Did you tie up the cables before you turned it over? They can get in the fans.


I have seen a LVPS failure when the HDM is not seated properly.


Walt
 

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Discussion Starter · #7 ·
Oddly enough, it's running fine now. I released the bolts so the rear heat sink can

hinge freely. Something in there must be touching.


The setup is going to be an involved one, I can tell you that.



And I may have a bad neck card to contend with, too. The black screen has a strong green background. But on all other test screens, the green background is black when it should be.


Not a G2 problem, I don't believe.


That's a bit odd.
 

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Check the clips that hold the convergence amp transistors to the heatsink. That extrusion isn't grounded to the chassis in any reliable way and may or may not always have a good connection. If one of the CVA transistor tabs are shorting to it you can get intermittant shorts on the 24V rails.
 

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Discussion Starter · #9 ·
What's bugging me now is the green issue.


I think I've got a green VIM input that's gone nuts.


If that's the case, I have trouble. The PJ is so close to the back wall that I can't change out

the VIM without dropping the machine first.


I'll be darned if I'll try to do it myself, especially twice in one day. I had help this morning,

but not now.


I guess I may not be watching many movies THIS week.


CJ
 

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CJ, it's very easy to remove tubes from a 9500 while it's on the ceiling, but I'm sure you already know that. Why not just drop the green tube itself and leave the others where they are. This will let you remove the green neck board as you need to, without having to drop the PJ also.
 

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Discussion Starter · #11 ·
Because it's not the green neck card that's the problem, it's the VIM.


If it were the neck card, then I'd ALWAYS have a bright green background, but only

when the PJ is looking at the VIM for the input signal does the background glow green.


Not the neck card. The VIM. And I can't do a thing about it today.


CJ
 

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Just FYI, I've had that LVPS problem here as well. Tse said in my post that it's usually a bad module connection, something like the AmPro 'open interlock' situation. Mine seemed to settle down after I ran it for 24 hours. I think some moisture got on the motherboard as I had it sitting in my storage locker. I also cleaned all module and interconnect contacts. It's been fine all weekend now.
 

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Check and redress all wiring and cables between the rear heat sink assembly and the main chassis. It's more likely a pinched wire or connector.


The two multi-pin connectors on the mother borad (going from the Vert/convergence boards) must have a protective sleeve isolating them from the heatsink. These same two ribbon cables can also be pinched easily, once the heatsink is restored to its original position.
 

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Chris,


Check the white plastic insulating strip. Make sure it's there and then make sure it's centered above the two ribbon connectors. It seems that they made the tolerance so tight, the solder side of the connector board presses HARD up against the underside of the heat sink. If you look at any Marquee, you'll see that the plastic insulator always has puncture marks from the pressure.


Bruce
 

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Discussion Starter · #15 ·
I'll check that for sure. And while I'm at it, I'll file down the solder side a bit anyway as insurance.


Chris
 

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I don't know if filing is a good idea. If the insulator strip is positioned right, that "should" be enough. It's a stupid design because they always catch and come off sometimes. I think what happens is that to work on a board, you have to remove it from the heat sink. To do that, you have to remove the heat sink clips, which are UNDER the insulator strip, so you haver to pull back the strip and it NEVER stays right again. ;)
 

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Woohoo congrats on getting it mounted, soon we'll be hearing your long awaited opinion on the NN/MP-5 combo with the 9".

Hope you can resolve your issues soon! Good Luck

I'll be in town on saturdays if you need help with mounting/unmounting.
 

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Discussion Starter · #18 ·
Well, I have to drop it again to change out the bad VIM. But it's easier to drop it now

with the hoist system. Not really a problem.


I've discovered a glycol leak in the green tube assembly, too. But one nice thing about a

9500 is that you CAN remove one tube assembly by itself. On an 8000 or 8500, you

can only remove all three at once, if it's ceiling mounted.


CJ
 

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Quote:
Originally Posted by Kamel407
Woohoo congrats on getting it mounted, soon we'll be hearing your long awaited opinion on the NN/MP-5 combo with the 9".

Hope you can resolve your issues soon! Good Luck

I'll be in town on saturdays if you need help with mounting/unmounting.
And I thought you were going to do this ? :confused:
 
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