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Agoraquest • View topic - KV-34XBR800 issues, first the 6/7 blink, then other troubles

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View topic - KV-34XBR800 issues, first the 6/7 blink, then other troubles

KV-34XBR800 issues, first the 6/7 blink, then other troubles

This Forum is questions on any problems you could have with your Sony Televsion set (i.e. Sony Wega grainess problem, cable problems, so forth)

Moderator: jttar

by Auburn Boy » Mon Jul 27, 2015 11:47 pm

Lately I've noticed (as referenced in my reading about this series of Sony) a white bar of haze that sweeps from right to left across the screen in the HDMI/DVI Input mode for 1080i signals..,

I noticed it first when setting up the DVI Input a few years ago, but the component video was "good enough" for me. But as I try to tune this beast up, I'm getting more picky about the detailed setup.

So, I tackled the SERVICE MODE settings that are recommended to fix this.

For XBR sets having been manufactured in Sep-Dec 2002, the hardware fix for this white haze effect "should" be in place.

The fix is to set High Definition Pass Through (HDPT) in the service menu to "0"

I did this (details on how to use service mode to do this are in the service manual for the D4-A chassis types.)

The white band is gone!! :) The video quality does not seem to be affected adversely!

Now on to the Power-on/Warmup issues.., Identify all the suspect electrolytic capacitors that might affect the start up picture quality. The effect is shown in these pictures:

Image

Image

Any hints on troubleshooting a problem like this will be greatly appreciated!

Neil
Auburn Boy
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by Auburn Boy » Tue Jul 28, 2015 2:28 am

I may have a lead on the power-on color problem.

On the CX board there are individual video amplifiers for the R, G, and B guns. They are powered by 200V and have decoupling caps on the power supply inputs. 10 uf at 250 Volts. It could be one of these babies or all three.

If there is ripple on the 200 V line, the ripple could propagate onto the V-out to each gun. This would be mixed with the color signal and could produce a wave superimposed on the horizontal deflection/gun output making a nice pattern that would die out as the voltage into the amplifiers stabilized..,

I'll have to apply a scope on these signals and see what happens at power-on.
Auburn Boy
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Joined: Tue Jun 23, 2015 9:45 am

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