Electronics repair - Toshiba TV-37C60 pincushion (hard one).

Author

Toshiba TV-37C60 pincushion (hard one).

Asimov

2005-04-16, 3:15 pm

"Jason D." bravely wrote to "All" (01 Apr 05 00:19:09)
--- on the heady topic of "Toshiba TV-37C60 pincushion (hard one)."

JD> From: jpero@sympatico.ca (Jason D.)
JD> Xref: aeinews sci.electronics.repair:44635

JD> This big tv has pincushion problem (bowed in), did basic checks on
JD> capacitors and diodes in series within horizontal circuit, ESR check
JD> on pincushion board (stand up) board next to this horizontal heatsink
JD> and scoped the board and adusted two pots for width and pincushion, it
JD> works as it should be.
[,,,]
JD> On pic with width pot, can change width no problem but pincushion
JD> seems to effect very limited, except it acted like bowed trapazoid
JD> which this chassis does not support.

JD> I"m stumped.

JD> Cheers,

Could be the diodes are leaky.

A*s*i*m*o*v

.... If all else fails, hurl it across the room a few times!

Jason D.

2005-04-16, 3:16 pm

UPDATE and NO FIX YET:

Swapped out one 2SC1815 transistor (barely weak) that is driving the
main amp pincushion transistor. Helped bit on that problem but had to
turn that pincushion pot all the way to one direction.

While working on other area of that TV to cool chassis off and turned
it back on, hey, one sided pincushion problem (right side bowed),
gradually straightens out within a minute. Left side is straight.

Not fixed yet! That one (slowly straightening out from cold start)
and pot all the way to one side should make pincushion into barrel
(bowed out) but yet it didn't.

Any other solutions?

Cheers, Wizard

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