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stefuel
Joined: 07 Mar 2006
Posts: 3353
Location: Green Harbor MA USA
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| Posted: Sun Oct 05, 2008 12:02 am Post subject: Frigged up AmPro question |
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I'm baffled. No error codes. Green tube is cranking full raster. I tried a new neck board at which time I discovered a massive HV leak off the corner of the splitter to the ground wire that goes from the bell of the tube to the neck board. I repaired that by fixing a leak in the green anode lead. To make sure I didn't cook the new neck board, I swapped with the blue. No love. I hooked it up to a Sencore tube analyzer/restorer and everything checks out. The tube shows a image but the whole face is illuminated. WTF???
Ooooh, and before Pete get's all over it like stink on poo, it's a 4000G not a X600. 
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Chip
A Barco is only a AmPro with training wheels
Card carrying member of the AVS chain gang.
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stefuel
Joined: 07 Mar 2006
Posts: 3353
Location: Green Harbor MA USA
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| Posted: Sun Oct 05, 2008 12:20 am Post subject: |
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Wow, 11 quick hits. OK admit it, how many of you vultures saw this and thought my 4600 bit the big one? 
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Chip
A Barco is only a AmPro with training wheels
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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: Sun Oct 05, 2008 1:58 am Post subject: |
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If you turn down the G2 on the neck board, does the tube face go out?
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stefuel
Joined: 07 Mar 2006
Posts: 3353
Location: Green Harbor MA USA
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| Posted: Sun Oct 05, 2008 3:20 am Post subject: |
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I suppose I should have said that but figured after how many years of owning and working on AmPro's, I'd be given credit for knowing that. No, it does not go away with lowering the G2. The whole face is lit up side to side and almost top to bottom. I have also noticed a deflection problem with the green as a spot is evident at power down.
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Chip
A Barco is only a AmPro with training wheels
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tse
Joined: 03 May 2006
Posts: 1014
Location: Sweatbucket, Fl.
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| Posted: Sun Oct 05, 2008 3:34 am Post subject: |
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If the neck card is good and the CRT checks good it doesn't make sense that the CRT cranks full on. Something is bad here. The Sony tubes had many problems with cathode to heater shorts. That causes full on. Bad neck card can cause the same thing. Just about has to be one or the other.
Scott
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stefuel
Joined: 07 Mar 2006
Posts: 3353
Location: Green Harbor MA USA
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| Posted: Sun Oct 05, 2008 3:54 am Post subject: |
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| tse wrote: | If the neck card is good and the CRT checks good it doesn't make sense that the CRT cranks full on. Something is bad here. The Sony tubes had many problems with cathode to heater shorts. That causes full on. Bad neck card can cause the same thing. Just about has to be one or the other.
Scott |
That's why I posted it here. The Sencore says no shorts, cut-off OK and emissions OK. I've swapped neck boards around with normal operating tubes with no luck. Is there any way bad magnetics on the tube could cause this? I have no idea how long this massive HV leak has been going on in the vicinity of the deflection coil. Knowing my brother, it could have been left on for a week that way
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Chip
A Barco is only a AmPro with training wheels
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Z-Photo
Joined: 07 Mar 2006
Posts: 2749
Location: Huntsville - Alabama
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| Posted: Tue Oct 07, 2008 1:33 pm Post subject: |
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Maybe your brother is paying you back for giving him an AMPRO....
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The Only GOOD AMPRO - is a Dead AMPRO.
wait - are they not all DEAD already?
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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 Oct 07, 2008 2:06 pm Post subject: |
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I'm guessing that it's internal to the tube. Swap tube positions and see if the problem moves with the tube?
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km987654
Joined: 25 Jul 2007
Posts: 2874
Location: Australia
TV/Projector: Barco BG809s
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| Posted: Wed Oct 08, 2008 9:30 am Post subject: |
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I have had a the same problem (minus the G2 as you described in my case G2 adjustment reduced tube output) on a Barco 1100 same tubes as the Ampro 4000 and its definitly the RGB Output boards in my case.
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stefuel
Joined: 07 Mar 2006
Posts: 3353
Location: Green Harbor MA USA
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| Posted: Wed Oct 08, 2008 10:34 am Post subject: |
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When I get a chance, I'll pull the whole assembly and re-test it on the bench. While it's out, I'll slide in a complete red tube assembly and see if it lights in it's place. It's a little baffling as the Sencore says the green tube is OK and I've tried 3 neck boards on it.
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Chip
A Barco is only a AmPro with training wheels
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