Panasonic CTP-31XF30 -- where is the vertical deflection criruit?
 

Panasonic CTP-31XF30 television, chassis No: ALEDP214. Set has intermittent
single horizontal line in the middle of the screen. From my reading, I
have determined that I should check the power supply to the vertical
deflection chip, replace electrolytic capacitors in the vertical
deflection circuit, and possibly check for a bad service switch.

My issue is locating these parts on the printed circuit boards. Can anyone
point me to a schematic of this set or identify the location of the
vertical deflection components???

On most Panasonic's its labeled IC451 (a LA7xxxx series chip) Your mileage
may vary though.

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Jeff Stielau
Shoreline Electronics Repair
344 East Main Street
Clinton,CT 06413
860-399-1861
860-664-3535 (fax)

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"ArdentGuy" wrote in message
lkaboutelectronicequipment.com...
Panasonic CTP-31XF30 television, chassis No: ALEDP214. Set has
intermittent
single horizontal line in the middle of the screen. From my reading, I
have determined that I should check the power supply to the vertical
deflection chip, replace electrolytic capacitors in the vertical
deflection circuit, and possibly check for a bad service switch.

My issue is locating these parts on the printed circuit boards. Can anyone
point me to a schematic of this set or identify the location of the
vertical deflection components???

Thanks for the hint about the vertical deflection chip usually being IC451.
I found a component labeled IC4351 but I can't make out any numbers on
the item and it doesn't look like an IC in that it is mounted on it's
edge. It is on the same board with all the PIP adjustment pots and
horizontal adjustments. IC4352 and IC4353 are also on the board...these
two are packaged like a standard "two-rows-of-pins" IC.

How many pins are usually on the vertical deflection chip? Can you give
me an actual chip number so that I can look it up (even if it is not the
correct one for my model)? I just want to see what one of these chips
looks like, how much they cost, and where to find one.

One more symptom to report...when the television is powered on, there are
5-6 white lines in the top of the picture. These white lines gradually
move up and out of the picture within the first 30-40 seconds. Does this
mean anything to anybody?

This may be unrelated, but just behind the flyback transformer is a zenor
diode that has discolored the PCB with some heat. The diode in questioned
is bordered by two capacitors: C553 and C554. C553 is discolored but as
it was leaning over zenor, it may have just been cooked by the diode.

I think I'm going to need some schematic help on this one. Does anyone
know what the diodes near C553 and C554 are used for?


THANKS FOR ANY HELP YOU CAN PROVIDE!
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