Curt Palme CRT Tech
Joined: 08 Mar 2006 Posts: 24396 Location: Langley, BC
TV/Projector: All of them!
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| Posted: Wed Oct 07, 2009 6:04 pm Post subject: Strange problem with NEC XG... |
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So I'm prepping an XG 110 for sale, in mint shape that I've sold, and I go to run it overnight before I send it. As soon as I power up, the red tube is shaking left/right bigtime. It's intermittent, but the red is shaking violently. I've seen this before, a bad system board, so I change:
-system board
-wave board
-Dconv board
-osc board
It's still doing it.
I then change the C and H shift boards. Still does it.
I disconnect the red yoke wires for the H shift and the C board, and it's still shaking. WTF? What else can cause a shift to the entire red image?
I did also notice that the G and B images did a tiny bit of shift, but I figured if I found the cause of the red shift, I'd find the root cause of the problem.
So in desperation, I swapped over the main H deflection yoke wires by one connector, so I put the R into the G socket, G into B, etc. I didn't think that would do anything, as all three main yokes are driven by the same signal, but that was it. I guess a tiny bit of corrosion on the yoke connectors caused the H shift/shaking. It's been solid for an hour now, rock solid on all resolutions. I'll use Caig cleaner on the connectors, but this is the very first time I've had issues with the NEC yoke connectors. Was I ever in a bad mood about 1/2 hour ago.
So... if you're experiencing convergence drift globally, or H shaking, you may not have a board failure after all.
The funny thing is, the problem would also have been cured had I changed the yoke wiring to ceiling mount, as that's the installation the customer will have. I noticed it while still set to floor mode, and I wasted 2 hours 'fixing' the problem.
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Mark_A_W
Joined: 15 Mar 2006 Posts: 3068 Location: Sunny Melbourne Australia
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| Posted: Thu Oct 08, 2009 8:36 am Post subject: |
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No, that's a common issue.
Seen that a few times here, happen to Jrobbo first - he figured it out.
If your image jumps L-R, reseat the deflection and C drive connectors.
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