| Author |
Message |
Elaine Benes
Joined: 25 Apr 2006
Posts: 1416
|
| Posted: Wed Dec 09, 2009 5:42 pm Post subject: |
|
|
| Tim in Phoenix wrote: | Curt
P43 green could behave like that, check the label on the tube.
. |
Wouldn't that be a funny one !
|
|
| Back to top |
|
 |
Curt Palme
CRT Tech
Joined: 08 Mar 2006
Posts: 24396
Location: Langley, BC
TV/Projector: All of them!
|
| Posted: Thu Dec 10, 2009 6:50 pm Post subject: |
|
|
OK, update again.
G2s remain solid at 595-600 volts per tube, regardless of contrast setting.
I swapped the video input lines, and the red still bumps up at high contrast. I'm using the internal test patterns, so that rules out the signals source and the VIM.
Swapped all neck boards with a good one, still the red goes bright. I did scope the VNB input and output, and it was inconclusive, so swapping boards and signal lines confirmed that the boards are OK.
Time to do some tube swapping. Maybe Tim is right. Give me an hour...
|
|
| Back to top |
|
|
Curt Palme
CRT Tech
Joined: 08 Mar 2006
Posts: 24396
Location: Langley, BC
TV/Projector: All of them!
|
| Posted: Thu Dec 10, 2009 8:04 pm Post subject: |
|
|
OK, strangely enough, it WAS the tubes. But... I dropped in a different R and G, and they did the same thing.
I then put in a full set of RGB from a set that I knew was flawless, and hte problem went away.
NOw I'll drop in the old tubes and the two others I put in one by one to see which one(s) it was.
|
|
| Back to top |
|
|
macgyver655
Joined: 22 Aug 2007
Posts: 8508
|
| Posted: Thu Dec 10, 2009 8:48 pm Post subject: |
|
|
See, if you tried what I suggested then you probably would of seen a variation in one of the tubes dots.... 
Now is it the tube, focus/astig coil, magnets, deflection coil? LOL
|
|
| Back to top |
|
|
Curt Palme
CRT Tech
Joined: 08 Mar 2006
Posts: 24396
Location: Langley, BC
TV/Projector: All of them!
|
| Posted: Thu Dec 10, 2009 9:19 pm Post subject: |
|
|
Well, hindsight is 20/20.
I reinstalled the original tubes, as well as the ones that I put in yesterday from stock.
As I'm in the middle of testing the R and B tubes that did not show the issue, leaving me with the greens, Tim calls.
He says 'check to make sure the greens aren't P43 tubes (fast recovery phosphor) as they can do this'. The tube is in front of me that I'm about to put back in the set, so I pop the plastic cover.. and it's a P43.
I go put the green tube into the set, sure enough, the problem is back.
That doesn't explain why the second green that I put in the set also showed the same issue... so I pop off the plastic cover on that tube... also a P43. Dammit! 
Now Tim wants $50 for his tech support. I told him he'd have to settle for dinner next time I came down to Az.
|
|
| Back to top |
|
|
Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
|
|
| Back to top |
|
|
Curt Palme
CRT Tech
Joined: 08 Mar 2006
Posts: 24396
Location: Langley, BC
TV/Projector: All of them!
|
| Posted: Thu Dec 10, 2009 9:41 pm Post subject: |
|
|
That's what I don't know. I just put a brand new P43 into a Barco 1209s for a customer, and zero issues. I guess it's when they are aged? I have not seen this in other P43 sets, and I've had a few through here.
I'm tagging these tubes and will play with them in another chassis. Main thing is that I've 'repaired' this one, and now know what it is.
That's what I like about this business, I'm always learning something, even if I end up putting a Philips screwdriver through my skull in the process.
|
|
| Back to top |
|
|
macgyver655
Joined: 22 Aug 2007
Posts: 8508
|
| Posted: Thu Dec 10, 2009 9:44 pm Post subject: |
|
|
|
So you replaced a P43 with another P43. LOL, what are the chances.
|
|
| Back to top |
|
|
Curt Palme
CRT Tech
Joined: 08 Mar 2006
Posts: 24396
Location: Langley, BC
TV/Projector: All of them!
|
| Posted: Thu Dec 10, 2009 9:56 pm Post subject: |
|
|
Yep, no scheittte! 
|
|
| Back to top |
|
|
Tim in Phoenix
Joined: 21 Oct 2006
Posts: 4409
Location: Phoenix
|
| Posted: Thu Dec 10, 2009 10:06 pm Post subject: |
|
|
Yup!
One learns how P43 behaves after installing a few dozen stereo projectors......
.
|
|
| Back to top |
|
|
Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
|
|
| Back to top |
|
|
Tim in Phoenix
Joined: 21 Oct 2006
Posts: 4409
Location: Phoenix
|
| Posted: Thu Dec 10, 2009 10:27 pm Post subject: |
|
|
Hello
It is a thermal issue, the tume is probably okay with contrast under fifty. LC tubes dissipate heat beater with the glycol and all.
.
|
|
| Back to top |
|
|
Curt Palme
CRT Tech
Joined: 08 Mar 2006
Posts: 24396
Location: Langley, BC
TV/Projector: All of them!
|
| Posted: Thu Dec 10, 2009 10:28 pm Post subject: |
|
|
Tim's into the sauce early...
(check your spelling!)
|
|
| Back to top |
|
|
macgyver655
Joined: 22 Aug 2007
Posts: 8508
|
| Posted: Thu Dec 10, 2009 10:31 pm Post subject: |
|
|
|
You mean he's beating on the heat with a tume?
|
|
| Back to top |
|
|
stefuel
Joined: 07 Mar 2006
Posts: 3353
Location: Green Harbor MA USA
|
| Posted: Tue Dec 15, 2009 1:19 am Post subject: |
|
|
This projector have a contrast modulation board installed???
_________________
Chip
A Barco is only a AmPro with training wheels
Card carrying member of the AVS chain gang.
|
|
| Back to top |
|
|
garyfritz
Joined: 08 Apr 2006
Posts: 12088
Location: Fort Collins, CO
|
| Posted: Tue Dec 15, 2009 1:30 am Post subject: |
|
|
|
So does the P43 green saturate like a blue tube!? Why else would it drop out at higher IREs?
|
|
| Back to top |
|
|
|
|
