CurtPalme.com Home Theater Forum

rotoscoped · Joined: 08 May 2017 Posts: 34 Location: Virginia

I've attached a photo of the neck board on the blue tube of my Marquee 9500LC and an "example" photo of a Marquee neck board from Tim's ETech Marquee LC tube removal guide (pic 18) for comparison.

When removing the blue tube several months ago (replacing glycol), I noticed a few areas on the neck board of what appear to be exploded transistors (?). I'm not sure if this is damage or some kind of modification (I don't know anything about circuit boards). The projector was and is running well, the damage (if it is damage) appeared to be done (versus an ongoing leak or burn), so I wasn't especially concerned. I took a picture, though, to ask about it here.

I've been using the PJ for about 18 months without any real issues. Occasionally, after a couple hours of use, the tubes will flicker on and off for a minute or two (ie. red tube will flicker off briefly, leaving just blue and green on for that moment, then red will come back on, and vice versa – usually a combination of all three cycling on and off). This will go on for a minute or two, then everything returns to normal. And sometimes weeks will pass without it happening at all. I've believed this to be related to the HDM – as adjusting and "reseating" the HDM on my ceiling mounted projector seemed to reduce or eliminate the flickering in the past. So perhaps unrelated, but I thought worth mentioning.

My neck board:

"Example" Marquee neck board from ETech site:

Tim in Phoenix · Joined: 21 Oct 2006 Posts: 4379 Location: Phoenix

Hello

Several parts have been replaced, and added, consistent with Mike Parker modifications. He placed black sealant in spots also.

It would be difficult to troubleshoot your flickering issue since it happens so fast and then clears itself.

**kal** · Posted: Wed Feb 19, 2020 2:58 pm Post subject:

To add to what Tim wrote: The black sealant / potting ("goop") you are seeing was added by Mike Parker on top of parts he replaces as part of his performance enhancements in order to hide the changes so that it can't easily be copied by others. They're not exploded transistors.

Can't help with the flickering.

Kal

**Curt Palme** · Posted: Sat Feb 22, 2020 7:32 pm Post subject:

Sounds to me that the problem is not CRT neck board related, but possibly CLM or HVPS. Pull all boards, use Caig D5 DeOxIt to clean all module contacts, and reassemble.

rotoscoped · Joined: 08 May 2017 Posts: 34 Location: Virginia

Thanks so much for the replies and information. I have some documentation from the previous owner about the neck boards and VIM having MP mods, but I was not able to confirm this on my own. Great to know.

The flickering hasn't cropped up in a couple weeks (usually it does only after the projector has been in use consecutively for 3 to 4 hours, and lately it hasn't been). I'll try the DeOxIt, Curt -- thanks for the tip. Just clean the areas where the circuit boards "seat" into the projector?

**Curt Palme** · Posted: Mon Feb 24, 2020 10:14 pm Post subject:

Yes, correct.