philips tv problem

[max]

Hi
I have Phlips 27"tv model 27pt543s37a.The problem is HOT burned.I check
hot(BU4508DX) and it was short between base collector and
emmiter.Replaced for a new one.Some forums says that cause this short
capasitor C2455.I replaced it as well.There was diode 6460 on the board
shorted also.Replaced it.So when I turn on tv looks like High Voltage to
CRT comes on but after few seconds it shorts HOT again and make inpulse
noise.Checked HOT again and it was completely shorted all over
again.Suspect bad flyback but not sure.Is anybody has a similar problem
with this model?thanks

 

[Arfa Daily]

Hi
I have Phlips 27"tv model 27pt543s37a.The problem is HOT burned.I check
hot(BU4508DX) and it was short between base collector and emmiter.Replaced
for a new one.Some forums says that cause this short capasitor C2455.I
replaced it as well.There was diode 6460 on the board shorted
also.Replaced it.So when I turn on tv looks like High Voltage to CRT comes
on but after few seconds it shorts HOT again and make inpulse
noise.Checked HOT again and it was completely shorted all over
again.Suspect bad flyback but not sure.Is anybody has a similar problem
with this model?thanks

Not particularly specific to this actual model, another couple of very
common causes of HO transistor failure in any HOP stage of this type, are
the coupling components in the base of the transistor, failure of which can
lead to a very bad waveshape which causes the transistor to over-dissipate
and fail in short order, and bad joints on the driver transformer, where one
is used. Also, carefully check for bad joints on the HOP transformer itself.
It's fairly hard to diagnose a faulty (as in shorted turns) transformer for
certain, without using either a ring tester, or having a replacement known
good one to try by substitution.

Arfa

 

[b]

Hi
I have Phlips 27"tv model 27pt543s37a.The problem is HOT burned.I check
hot(BU4508DX) and it was short between base collector and
emmiter.Replaced for a new one.Some forums says that cause this short
capasitor C2455.I replaced it as well.There was diode 6460 on the board
shorted also.Replaced it.So when I turn on tv looks like High Voltage to
CRT comes on but after few seconds it shorts HOT again and make inpulse
noise.Checked HOT again and it was completely shorted all over
again.Suspect bad flyback but not sure.Is anybody has a similar problem
with this model?thanks

possibly also the line o/p transformer is duff.
next time, wire a 60w bulb across c-e of the HOT without the
transistor. measure the voltage, should probably be about 130-150v for
this size set.
-B