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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Jason D.
 
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Default Hitachi 55FX20B UNIQUE intermttent misconvergence.

Thought three individual red, green and blue colors displaces when
convergence intermittently fails, admittedly true except:

Not this one!

The set takes the cake for red and blue moving TOGETHER smoothly to
left slightly then drifts back together with green just like double
vision. Made me go "oooh".

Seen this before? I have already reworked the digital convergence
generator module by redid solder jobs and several caps, checkeded them
and put some new caps as well. Very professional job by the way.
This is small metal box on the bottom shelf under CRT assembly. Redid
the solder connections on main deflection board & convergence amps.
Impact tests and wiggling wires gives no results. Last repair lasted
1 and half months then that same problem came back.

Cheers, Wizard
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Art
 
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Default Hitachi 55FX20B UNIQUE intermttent misconvergence.

Try resoldering the inter board connections between the signal,
power/deflection, and convergence assemblies. Seen some of these have very
silght ring cracks that affect registration communications to/from MPU
DAC as well as a few other unique symptoms.
wrote in message
ups.com...
If it's running NTSC, which is 59.97 Hz refresh, some sort of 60 Hz EMI
could be the cause. Also since the thing runs on 60 Hz power, it may be
a power supply fault. For this to be true the set is probably off
centering, and is being compensated for electronically.

I would have a serious look at your grounds, and also determine
unequivocably the it is the red and blue rather than the green
affected. It's less likely that the red and blue are affected equally.

What I said about grounds still goes, but also make sure you don't have
a line leakage problem.

It is interesting, I'd be interested to see the final resolution.

JURB



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