19" KDS computer monitor (flat
screen),model:XF-9P,chassis:C812,year:Feb 2002,LG Electronics
(Goldstar) CRT,UL Listed:7K04 (Sampo).Problem no power I found
Q706=2SC5584=NTE2533=SMPS x-fmr transistor is shorted due to cracked
solder connections at the base signal drive components:

R723
D705
R734
D706
R720
R721
T701=horizontal driver x-fmr

I replaced Q706 the monitor powered up with hv for a second then a
chirping with an increasing rate from the power supply so I now
D706=BY459F (diode connected to collector and emitter of Q706) is
shorted but the new Q706 is fine.
I would like any common repair tips for this chassis before I replace
D706 and I would like a possible NTE substitute as NTE does not list
one and this diode comes in a rectangular case that is screwed on same
chassis heatsink as the SMPS x-fmr transistor (Q802=2SC5339).

I don't repair computer monitors because usually about 70% of them have
defective flybacks but I rang this one and it's fine.Thanks in advance.
Note:this unit is similar to 19" HP computer monitor M90
model6433A,chassis:C812

Sidney
Dartmouth,Nova Scotia
Canada

O
|\ __O
_|_| \

" bravely wrote to "All" (13 Sep 05 08:17:41)
--- on the heady topic of "19" KDS monitor model:XF-9P,chassis:C812"

si From:
si Xref: core-easynews sci.electronics.repair:342035

si 19" KDS computer monitor (flat
si screen),model:XF-9P,chassis:C812,year:Feb 2002,LG Electronics
si (Goldstar) CRT,UL Listed:7K04 (Sampo).Problem no power I found
si Q706=3d2SC5584=3dNTE2533=3dSMPS x-fmr transistor is shorted due to cracked
si solder connections at the base signal drive components:

si R723
si D705
si R734
si D706
si R720
si R721
si T701=3dhorizontal driver x-fmr

si I replaced Q706 the monitor powered up with hv for a second then a
si chirping with an increasing rate from the power supply so I now
si D706=3dBY459F (diode connected to collector and emitter of Q706) is
si shorted but the new Q706 is fine.
si I would like any common repair tips for this chassis before I replace
si D706 and I would like a possible NTE substitute as NTE does not list
si one and this diode comes in a rectangular case that is screwed on same
si chassis heatsink as the SMPS x-fmr transistor (Q802=3d2SC5339).

si I don't repair computer monitors because usually about 70% of them
si have defective flybacks but I rang this one and it's fine.Thanks in
si advance. Note:this unit is similar to 19" HP computer monitor M90
si model6433A,chassis:C812

si Sidney
si Dartmouth,Nova Scotia
si Canada


When the hot and damper want to self destruct it is a sign the fbk
pulse is likely peaky. This may be caused by an open in the peak
control network, often just a resistor with a high voltage disk cap.
Check the base drive to the hot has the proper waveshape. Check
derived supples for shorts, i.e. vertical, etc. No specific tips for
this model but they are pretty much the same. Why are you fixing it?

A*s*i*m*o*v

.... "Bother!" said Pooh, as he saw the sparks and smelled the smoke.

ha scritto:

19" KDS computer monitor (flat
screen),model:XF-9P,chassis:C812,year:Feb 2002,LG Electronics
(Goldstar) CRT,UL Listed:7K04 (Sampo).Problem no power I found
Q706=2SC5584=NTE2533=SMPS x-fmr transistor is shorted due to cracked
solder connections at the base signal drive components:

R723
D705
R734
D706
R720
R721
T701=horizontal driver x-fmr

I replaced Q706 the monitor powered up with hv for a second then a
chirping with an increasing rate from the power supply so I now
D706=BY459F (diode connected to collector and emitter of Q706) is
shorted but the new Q706 is fine.
I would like any common repair tips for this chassis before I replace
D706 and I would like a possible NTE substitute as NTE does not list
one and this diode comes in a rectangular case that is screwed on same
chassis heatsink as the SMPS x-fmr transistor (Q802=2SC5339).

You want a xref for that diode ? You may try a BY399 or BY499.

I.

--
I.