CurtPalme.com Home Theater Forum

epatsellis · Joined: 18 Aug 2010 Posts: 35 Location: Central IL

After making signigicant progress this week, changed out both B and G tubes on my 135, but the grayscale is way off. Then again, it was off before with the original tubes, but they were toasted enough that I really didn't care. Now with nearly minty new tubes, it's time to actually use some of the test equipment on my bench and actually (hopefully) get the w/b right.

Anybody have a copy of the XG135 service manual, or a pdf of the white balance procedure?

**Curt Palme** · Posted: Thu Nov 20, 2014 2:38 pm Post subject:

Whatever you do, DO NOT follow the service manual procedure. Even Doug Baisey couldn't figure it out. Use the G2 setup method on the main site. All you need is a ramped gray scale and a voltmeter.

**kal** · Posted: Thu Nov 20, 2014 3:31 pm Post subject:

+1 to that.

I had an XG for a while some years back that had some white balance issues and tried to go through the service manual instructions with my 'scope and voltmeter and couldn't get the results that were expected to work at all like they were supposed to according to the manual. Stay away.

Kal

epatsellis · Joined: 18 Aug 2010 Posts: 35 Location: Central IL

Curt,
I'm guessing setup G2, then colorimeter to fine tune w/b?

epatsellis · Joined: 18 Aug 2010 Posts: 35 Location: Central IL

Curt, (or anybody else...)

With AKB switch in test position, G2 Ref is 2.5 +-.1v, when switched to normal, ref goes to 5v or so and triggers a bf fault display on the back of the projector. Any ideas??? Last time I ran this projector, I remember going through the G2 process and it was fairly straightforward. I do have a complete spare (known working) projector to swap from as well.

( I really have to find a copy of the XG service manual to get a better understanding of the sub systems and how they relate to each other...these are a far cry from the Ampros)

**Curt Palme** · Posted: Fri Nov 21, 2014 4:25 am Post subject:

Something is sending the drive way high. Is any one tube far brighter than the others? try turning off one tube at a time. Usually you can trick the set into staying on by muting one or more tubes. Definitely the test point reference should stay pretty close to 2.5 in the normal position.

epatsellis · Joined: 18 Aug 2010 Posts: 35 Location: Central IL

If you register a new signal, the g2 is equally high on all 3 tubes, the set doesn't shut down, just displays the fault. I can get a reasonable image by manually bringing the black bias down, much as setting the g2 on a chassis without AKB, but I'd rather make it right if I can. Unknown history on these chassis there is the possibility somebody golden screwdrivered them, thinking they were improving things. In which case I don't know if I want to go through the entire calibration of the video chain.

Depending on my available time, I may drop the tubes into my spare chassis and see if it works ok, a shotgun approach (more like an easy Hail Mary), but the most expedient. The alternative would be one of the two 3600’s I have here with fresh tubes, though the NEC image quality has me suckered in, so far.

epatsellis · Joined: 18 Aug 2010 Posts: 35 Location: Central IL

well, it was the first chassis. the former "spare" is now the primary, all the G2 voltages are in the range of being correct, hopefully this afternoon I'll get the G2 dialed in. Given I have a spare, If anybody has the on video chain calibration scanned or as a PDF, I'm more likely to give it a go now.

erie