BEKO TV ( chassis 12.7 ) HELP
 

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-

BEKO TV ( chassis 12.7 ) HELP
 

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

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-

The circuit diagram for the 12.7 chassis is available he

http://www.eserviceinfo.com/download.php?fileid=2679

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
--
Please remove one 'i' from my address when replying by email.

BEKO TV ( chassis 12.7 ) HELP
 

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

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.