Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

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Default Sony KV-36XBR800 like keystone pix, bad purity also.

The CRT, & yoke seems ok because if I put a small magnet near the
little coils on the pin correction pcb, the pix is near perfect.
The four corners are out of purity a bit, & overall convergence is bad
throughout pix, & pix is rounded on top & bottom, but height, & width
is ok. The CRT is fine, I'm thinking the drive board is bad, or more
likely, not getting correction pulses, or voltages from the main
board. Didn't have time to check. Any tips on this? And a service
manual? Thanks, Dani.
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Default Sony KV-36XBR800 like keystone pix, bad purity also.

I cannot tell you the exact components in your TV, or any TV without
actualy troubleshooting it in detail. With the service manual and a
detailed understanding of how the electronics of the TV works, and the
proper instrumentation it is possible to troubleshoot the set.

Some very common causes are electrolytic caps in the scan and pin amp
drive ciruits. These caps can be checked by using an ESR meter, or
shot-gunning it by changing them all. On more rare occasions it can be
semiconductors or other type of support components in the pin and scan
drive areas. On more rare occasions I have seen deflection yokes and
or the horizontal output transformer (flyback) cause problems. I have
also seen, but very rare, a damaged shadowmask in the CRT cause pin
and purity errors.

What you are doing with the magnet is offsetting some of the scan
distortions. This will cause other distortions to appear when trying
this. In a properly working set, small magnets of the proper spec are
used around the CRT and yoke area for some pin, convergence, and
purity correction. This type of adjustment requires very good skill
from a lot of practice.

Considering the age of your set, I would not be encouraged to invest a
lot of money and time in to it.


Jerry G.


On Nov 29, 1:48*pm, Dani wrote:
The CRT, & yoke seems ok because if I put a small magnet near the
little coils on the pin correction pcb, the pix is near perfect.
The four corners are out of purity a bit, & overall convergence is bad
throughout pix, & pix is rounded on top & bottom, but height, & width
is ok. The CRT is fine, I'm thinking the drive board is bad, or more
likely, not getting correction pulses, or voltages from the main
board. Didn't have time to check. Any tips on this? And a service
manual? Thanks, Dani.


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