CurtPalme.com Home Theater Forum

MarchingCRT · Joined: 14 Nov 2008 Posts: 36 Location: Baltimore, MD

I have a nine inch marquee and need to clean the fungus out of the green tube. The machine is mounted on the ceiling. Can I safely take the tube out without taking the whole projector down? Do I have to remove all the tubes at the same time? This projector started out as an 8500 I bought from Curt many years ago. I scored a set of 9 inch tubes a few years ago and made the swap, but I cannot remember exactly the process. I just want to make sure I don’t loosen something and the tubes come falling out!!

Thx
Trent

gjaky · Joined: 05 Jun 2010 Posts: 2802 Location: Budapest, Hungary

You can remove the tubes safely one by one even if it is ceiling mounted. You have to remove all the covers, there is a bar on the top of the tubes, but each tube is held in place by the two screws those can be found at the "foot" of the tubes. Make sure to remove all the electrical connections (neckboards, astig, H & V deflection, convergence, focus, HV) before trying to remove the tube.

Tim in Phoenix · Joined: 21 Oct 2006 Posts: 4409 Location: Phoenix

Guys

Take the lens off first, it is fifteen pounds alone. You will need a long 9/64 allen driver; Xcelite makes a nice kit. Unplug everything to the green tube, remove the neckboard, unplug the pink anode lead and anything in the way. I would remove the horizontal deflection and focus boards and the sleeves they sit in. Then, with someone holding the twenty pound weight of the tube, remove the two "footer" bolts, 3/16 allen. The tube should drop down under its weight alone.

Replace old glycol with 90/10 mix of triethylene glycol and distilled water, you will need about 22 fl. ounces. A plastic squirt tip bottle is useful. Replace fill hole screws with stainless steel if necessary. Removing the old bellows is a problem, the c element lens often sticks to it and you end up slicing it away and replacing it.

I can replace bellows and glycol on tubes shipped to Scottsdale 85258

Tim Martin, E-Tech Systems Scottsdale

480 253 2781 please text me first

ehometech8022@yahoo.com

MarchingCRT · Joined: 14 Nov 2008 Posts: 36 Location: Baltimore, MD

Thank you both!! This jogs my memory. I am pretty sure when I put in the tubes I roughed in the mechanical portion on a bench and then removed the tubes, mounted the chassis and remounted the tubes so we weren’t lifting all that weight at once. Tim, I will consider sending you the tube. I have a spare I can throw in so I don’t miss any 🏈 for now😎. It ‘looks’ fine sitting on my shelf. Guessing it will work fine. Thanks again for the info. I will post back with my progress. When I make some progress 😅

MarchingCRT · Joined: 14 Nov 2008 Posts: 36 Location: Baltimore, MD

I have switched out the tube. I took my time and it went smoothly. This green is much brighter than the other one. It could be that I had the input lead to the HV splitter on the wrong terminal. I learned last night the correct one is marked "in". I would guess that is why the other green seemed weaker? I would have had only a 25% chance of hooking it up correctly when I swapped all the tubes out years ago not knowing this tidbit. I have gone through and reset everything and done a decent job with the magnets. Looking forward to adjusting greyscale and watching!

Thank you again for the guidance!

**Curt Palme** · Posted: Thu Jan 20, 2022 11:19 pm Post subject:

No the lead locations on the splitter have nothing to do with brightness. The replacement green tube has more emission than the original. Check your filament voltage, if it has a LVPS with the drifting filament control in it, then the filament voltage will drift upwards, killing tubes. The filament should read no more than 6.5 volts, ideally 6.35