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poen
Joined: 21 Dec 2012 Posts: 51
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Link Posted: Tue Aug 17, 2021 5:54 pm Post subject: Sony 1292 - Blue Tube on/off - very low brightness |
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Dear CRT experts,
I have a Sony 1292 which I have been using for about a year with a lot of pleasure.
Yesterday the blue tube started to go on/off once I would start to play a movie, with lower 'load' such as youtube / random websites it was still fine.
An hour later blue went off completely.
Today blue is back on, but not bright at all, looks to be stuck at around 20% of it's original brightness.
What could this be?
I have a few blue tubes as spares, could it simply be the blue tube dying or could the problem be somewhere else?
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Curt Palme CRT Tech
Joined: 08 Mar 2006 Posts: 24296 Location: Langley, BC
TV/Projector: All of them!
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Link Posted: Tue Aug 17, 2021 6:49 pm Post subject: |
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Usually it's the CRT video board, or the ribbon cable between the video output board, and the driver board. Check the ribbon connections first, as that's the easiest.
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poen
Joined: 21 Dec 2012 Posts: 51
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Link Posted: Tue Aug 17, 2021 7:10 pm Post subject: |
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Curt Palme wrote: | Usually it's the CRT video board, or the ribbon cable between the video output board, and the driver board. Check the ribbon connections first, as that's the easiest. |
Thanks for getting back to me so fast.
Took the ribbon out, cleaned it a bit- put it back, same story- red/green 100% and blue ~20%.
Should I replace the blue ribbon completely?
What else, besides the ribbon could be the problem- how could I be sure the blue tube is not 'done' ?
Regarding the video board, which one would that be on the 1292?
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Curt Palme CRT Tech
Joined: 08 Mar 2006 Posts: 24296 Location: Langley, BC
TV/Projector: All of them!
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Link Posted: Wed Aug 18, 2021 2:21 pm Post subject: |
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the video board is the square metal cage over the tube CRT socket (or behind it, I can't remember). I'd swap the tube to see what happens.
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poen
Joined: 21 Dec 2012 Posts: 51
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Link Posted: Sat Aug 21, 2021 8:02 am Post subject: |
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Curt Palme wrote: | the video board is the square metal cage over the tube CRT socket (or behind it, I can't remember). I'd swap the tube to see what happens. |
I have changed the complete video board - the metal box that has the wires moving to the neck boards.
Still the same problem.
What I will do next:
1. Change blue ribbon cable
2. Change blue tube
The odd thing I noticed was, while blue is very dimmed red and green are MUCH brighter, before I could kind of look into the light but now this is impossible, it's like the power from the blue goes more into the red and green. Could this 'effect' indicate something you would know?
I have a total of 6 1292's so swapping parts is no problem with the exception of the PSU.
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poen
Joined: 21 Dec 2012 Posts: 51
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Link Posted: Mon Aug 23, 2021 7:02 pm Post subject: |
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@Curt do you perhaps have an idea what the increase in brightness in red/green can cause and low in blue?
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helfriwj
Joined: 29 Oct 2006 Posts: 48 Location: Pittsburgh,PA
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Link Posted: Fri Jul 14, 2023 3:51 pm Post subject: |
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I am having a problem with the green tube not turning on could you show a picture of the ribbon cable?
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