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Curt Palme
CRT Tech
Joined: 08 Mar 2006
Posts: 24396
Location: Langley, BC
TV/Projector: All of them!
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| Posted: Mon Mar 24, 2008 2:29 pm Post subject: |
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The G2s do, the black multicable doesn't.
Did you swap the RCAs at the VNB though? Not at the VIM?
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Heywood Jablome
Joined: 12 Mar 2006
Posts: 1548
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| Posted: Mon Mar 24, 2008 2:47 pm Post subject: |
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Both, no apparent effect either time.
What is the G2 line? The 1/8" push-on with the color coded heatshrink near the center of the board?
_________________
"Those countries which lag behind in industry, in the application of mechanics and technical chemistry, in the careful selection and utilization of natural products, where the respect for such activities does not permeate all classes of society, will unfailingly decline in prosperity. They will sink faster when neighbor states, with an energetic exchange between science and industry, go forward with renewed vitality."
-- Baron Alexander von Humboldt: 1769-1859
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Curt Palme
CRT Tech
Joined: 08 Mar 2006
Posts: 24396
Location: Langley, BC
TV/Projector: All of them!
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| Posted: Mon Mar 24, 2008 3:13 pm Post subject: |
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Yes, that's it. Swap those between tubes.
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Tim in Phoenix
Joined: 21 Oct 2006
Posts: 4409
Location: Phoenix
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| Posted: Mon Mar 24, 2008 5:27 pm Post subject: |
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| Nashou66 wrote: | | Tim in Phoenix wrote: | Hello
Troubleshooting Marquee Video Problems Without A Scope
One does not always have the luxury of a dual trace scope on the road,
here are a few norms to test for if your Marquee has high voltage and
picture problems, like flashing, or no pix at all, or one color is weak:
Vim Mini Coax Levels, Unplugged From VNB:
With CONT of 40 and BRITE of 40, the tip of the mini coax feed
gives 110mv with internal stairstep, 255mv on white field.
Internal Pattern Sequence is 1) Hatch plus Dots,
2) Dots Only, 3) Stairstep, 4) Full White, 5) Source
G2 Values and Voltage, measured at tip of VNB R76:
G2 of 40 gives +375vdc
45 +415vdc
50 +462vdc
55 +510vdc
60 +555vdc
65 +600vdc
70 +646vdc
Fluke DVM dc limit is 655vdc and goes into alarm mode.
Brightness Control Line to VNBs, P13 Pin 8:
BRITE of 0 gives +2.02vdc
10 +1.59vdc
20 +1.19vdc
30 +0.81vdc
40 +0.37vdc
50 - 0.02vdc
60 -0.44vdc
We have observed Marquees with leaking glycol where this control
voltage was shorted to +5v on the MB and as a result the tubes shut
down for no apparent reason; you would think you had a bad VIM
or neckboard but it was not so.
Tim at E-Tech Systems 480 368 7434 http://www.etechvideo.com/ |
Tim what would these procedure's be if you have a scope...out of curiosity.
Athansios |
Hello
The VIM coax would be waveforms; the other readings would still be DC; the whole idea is to make some determinations when you don;t have a scope.
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Tim in Phoenix
Joined: 21 Oct 2006
Posts: 4409
Location: Phoenix
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| Posted: Mon Mar 24, 2008 5:30 pm Post subject: |
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Hello
I would check filaments again. Heywood's measurements suggest the tube went weak suddenly. Any other theories?
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Heywood Jablome
Joined: 12 Mar 2006
Posts: 1548
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| Posted: Mon Mar 24, 2008 9:03 pm Post subject: |
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Perhaps its' noteworthy that the line width of the internal test patterns is much narrower for the green? Green is easily 1/3 the line width of red or blue (with approximately equivalent optical focus.)
I'll check on the G2 tonight.
_________________
"Those countries which lag behind in industry, in the application of mechanics and technical chemistry, in the careful selection and utilization of natural products, where the respect for such activities does not permeate all classes of society, will unfailingly decline in prosperity. They will sink faster when neighbor states, with an energetic exchange between science and industry, go forward with renewed vitality."
-- Baron Alexander von Humboldt: 1769-1859
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CRT_Ben
Joined: 28 Aug 2006
Posts: 1684
Location: Northern Virginia
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| Posted: Mon Mar 24, 2008 9:25 pm Post subject: |
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| Curt Palme wrote: | | Did you swap the RCAs at the VNB though? Not at the VIM? |
Just curious, how would this make any difference? Is it not just a straight shot (unbroken, untapped wire) from the VIM to the VNB?
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comm
Joined: 09 Mar 2006
Posts: 46
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| Posted: Mon Mar 24, 2008 9:53 pm Post subject: |
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| CRT_Ben wrote: | | Curt Palme wrote: | | Did you swap the RCAs at the VNB though? Not at the VIM? |
Just curious, how would this make any difference? Is it not just a straight shot (unbroken, untapped wire) from the VIM to the VNB? |
It is a straight shot. I think, this way would test to see if a cable was bad.
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Heywood Jablome
Joined: 12 Mar 2006
Posts: 1548
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| Posted: Tue Mar 25, 2008 12:10 am Post subject: |
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Well, I've tried different iterations of G2, mini-RCA, and VNB swappery and I can't get anything like appropriate green output. Since I appear to be pulling tubes anyway, I'm going to try flipping the whole tube and see if the problem lies with the black multi-cable (or more likely the components lying behind the black multi-cable.)
_________________
"Those countries which lag behind in industry, in the application of mechanics and technical chemistry, in the careful selection and utilization of natural products, where the respect for such activities does not permeate all classes of society, will unfailingly decline in prosperity. They will sink faster when neighbor states, with an energetic exchange between science and industry, go forward with renewed vitality."
-- Baron Alexander von Humboldt: 1769-1859
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Heywood Jablome
Joined: 12 Mar 2006
Posts: 1548
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| Posted: Tue Mar 25, 2008 12:11 am Post subject: |
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Oh... to answer Tims' last question: I've been checking P14 all the while... rock solid at 6.35+-.02
_________________
"Those countries which lag behind in industry, in the application of mechanics and technical chemistry, in the careful selection and utilization of natural products, where the respect for such activities does not permeate all classes of society, will unfailingly decline in prosperity. They will sink faster when neighbor states, with an energetic exchange between science and industry, go forward with renewed vitality."
-- Baron Alexander von Humboldt: 1769-1859
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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Curt Palme
CRT Tech
Joined: 08 Mar 2006
Posts: 24396
Location: Langley, BC
TV/Projector: All of them!
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| Posted: Tue Mar 25, 2008 12:32 am Post subject: |
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| Heywood Jablome wrote: | | Well, I've tried different iterations of G2, mini-RCA, and VNB swappery and I can't get anything like appropriate green output. Since I appear to be pulling tubes anyway, I'm going to try flipping the whole tube and see if the problem lies with the black multi-cable (or more likely the components lying behind the black multi-cable.) |
Yup, that's the next best step. Me guesses it's the tube..
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stefuel
Joined: 07 Mar 2006
Posts: 3353
Location: Green Harbor MA USA
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| Posted: Tue Mar 25, 2008 1:16 am Post subject: |
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JT, why don't you come over and grab a Marquee Red that I have here and slide it in place of the green and see itf the red has good output.
_________________
Chip
A Barco is only a AmPro with training wheels
Card carrying member of the AVS chain gang.
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Heywood Jablome
Joined: 12 Mar 2006
Posts: 1548
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| Posted: Tue Mar 25, 2008 1:16 am Post subject: First the blue wept... |
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Then I wept...
Looks like Tim may get the prize:
All three bellows have been weeping glycol. The red and green just enough to wet the bottom of the LC chamber where it meets the bottom plate, but the blue has a clearly visible snail trail emanating from the bottom of the LC chamber all the way past the edge of the aluminum belly-fan cover.
That said, I can't actually see where the glycol went after that... this unit had been turned up about 30 degrees most of its' life in that big RP chassis so odds are it hit the TOP of the upper mobo, but I can't see any signs on the circuit board itself.
I'm planning on pulling the top motherboard and looking under it. Question: Should I tempt fate and try the green on one side or the other, or should I keep stripping?
_________________
"Those countries which lag behind in industry, in the application of mechanics and technical chemistry, in the careful selection and utilization of natural products, where the respect for such activities does not permeate all classes of society, will unfailingly decline in prosperity. They will sink faster when neighbor states, with an energetic exchange between science and industry, go forward with renewed vitality."
-- Baron Alexander von Humboldt: 1769-1859
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Curt Palme
CRT Tech
Joined: 08 Mar 2006
Posts: 24396
Location: Langley, BC
TV/Projector: All of them!
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| Posted: Tue Mar 25, 2008 1:34 am Post subject: |
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OK, if that's the case, use a toothbrush and isopropyl alcohol and take out all three tubes and the top motherboard under the focus and H board. That will expose the backplane motherboard. You should be able to see if any glycol dripped down it, usually under the system chip and hte 64 pin module contacts. Flush the CRAP out of the chip with the alcohol, like 5 times. THen do it again..
Flush under the module contacts, with luck nothing got under them. It's a royal PITA to get the backplane out, do it in the chassis. It's a 100 screw 2 hour job to take the board out, but it can be done. I had to do it to a 9500 once. I've got spare boards here if one is too far gone, but I'll bet flushing it will work fine and bring back the green brightness.
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Heywood Jablome
Joined: 12 Mar 2006
Posts: 1548
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| Posted: Tue Mar 25, 2008 1:36 am Post subject: |
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Looks like the red wept enough to leave a bit of a trail too... (2nd, wide angle pic. The closeup is of the blue trail going into the mounting tab for the HDM.)
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_________________
"Those countries which lag behind in industry, in the application of mechanics and technical chemistry, in the careful selection and utilization of natural products, where the respect for such activities does not permeate all classes of society, will unfailingly decline in prosperity. They will sink faster when neighbor states, with an energetic exchange between science and industry, go forward with renewed vitality."
-- Baron Alexander von Humboldt: 1769-1859
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Heywood Jablome
Joined: 12 Mar 2006
Posts: 1548
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| Posted: Tue Mar 25, 2008 1:39 am Post subject: |
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Any credence to the dishwasher idea? With or without detergent? 
_________________
"Those countries which lag behind in industry, in the application of mechanics and technical chemistry, in the careful selection and utilization of natural products, where the respect for such activities does not permeate all classes of society, will unfailingly decline in prosperity. They will sink faster when neighbor states, with an energetic exchange between science and industry, go forward with renewed vitality."
-- Baron Alexander von Humboldt: 1769-1859
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Zebu Fellenz
Joined: 21 Dec 2006
Posts: 2567
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| Posted: Tue Mar 25, 2008 1:46 am Post subject: |
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Look on the bright side,
The tube may be OK, worst case you'll need to get some new boards (8500 chassis with burnt tubes) or best case it will just need a thorough cleaning.
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Tim in Phoenix
Joined: 21 Oct 2006
Posts: 4409
Location: Phoenix
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| Posted: Tue Mar 25, 2008 1:59 am Post subject: |
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Guys!
What is odd is that the key voltages on the neckboard all seem within limits. I wonder if one of the 85 volt rails got some glycol on it........
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Nashou66
Joined: 12 Jan 2007
Posts: 16171
Location: West Seneca NY
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| Posted: Tue Mar 25, 2008 2:06 am Post subject: |
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The thing is it was working before the re initialization and if it was a glycol related problem i think the problem would have showed up earlier. And like tim said the key voltages seem ok. you should have swaped the green tube to ......say the reds location and tried it there. then you would know for sure if it was the tube. Hopefully I am wrong and its not the tube.
Athanasios
_________________
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