BEKO TV ( chassis 12.7 ) HELP

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- b
  
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posted
17 years ago

Tue, Feb 27, 2007 11:05 PM

Have this set: 21t44txm, with Beko 12.7 chassis. Replaced line transformer as it was smoking. Set now works, but the remaining problem now is that the picture (raster) is shifted down about quarter of an inch or more.Annoyingly just enough to be noticeable.

Have tried entering service mode (menu + 9301) but the adjustments thre are for things like IF and tuner type and hotel mode rather than picture adjustments. Is there a separate menu I need? There are no pots on the main pcb, so there must be a menu somewhere..... cheers. B-

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- Franc Zabkar
  
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posted
17 years ago

Wed, Feb 28, 2007 5:50 AM

On 27 Feb 2007 15:05:45 -0800, "b" put finger to keyboard and composed:

The circuit diagram for the 12.7 chassis is available here:

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A DC bias voltage appears to be injected into the vertical yoke via R503. It originates from pin 10 of the FBT. Maybe the replacement FBT is slightly different in construction, or maybe C564 is dry? Or maybe you could play with the value of R503? I'd check all the caps around the vertical IC before changing anything, though.

- Franc Zabkar

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posted
17 years ago

Wed, Feb 28, 2007 2:23 PM

On 27 feb, 21:50, Franc Zabkar wrote: snip

Thanks Franc. Will check that out. Also suspect r506 , 150k off pin 4 of the vertical chip, seems to be repsonsible for similar symptoms on other models.

-B.