Orion tv S21, with STR58041 regulator, how to be sure it is

J

Jim Lazzaro

Guest
This TV does not start up; it has standby light on but no voltages are
present on the secondary of the smps transformer.
I have so far replaced leaky caps and tested for other faulty parts
but all is clear, except offcourse it doesn't run.
I suspect the power regulator STR58041 is playing up; Before replacing
it I would like to be sure that I checked it properly.
Any advice on this point:
the schematic shows that 0.4 v should be at pin 2 (base drive) and my
uncertainty is whether this can only be measured on powering on or it
should be there continuosly. I understand this voltage would cause the
regulator to start the power supply alltogether.
I hope expertise comes my way on this troublesome repair.
Thanks
Jim
 
Hi,

Are you sure it the correct model number?

Check horizontal output transistor.

Rudolf

"Jim Lazzaro" <Jim_Lazzaro@hotmail.com> wrote in message
news:fae7122f.0407252013.26eba07e@posting.google.com...
This TV does not start up; it has standby light on but no voltages are
present on the secondary of the smps transformer.
I have so far replaced leaky caps and tested for other faulty parts
but all is clear, except offcourse it doesn't run.
I suspect the power regulator STR58041 is playing up; Before replacing
it I would like to be sure that I checked it properly.
Any advice on this point:
the schematic shows that 0.4 v should be at pin 2 (base drive) and my
uncertainty is whether this can only be measured on powering on or it
should be there continuosly. I understand this voltage would cause the
regulator to start the power supply alltogether.
I hope expertise comes my way on this troublesome repair.
Thanks
Jim
 
Suspect power reg.Check for broken legs on this ic near the main housing.
Cheers
Joe

"Jim Lazzaro" <Jim_Lazzaro@hotmail.com> wrote in message
news:fae7122f.0407252013.26eba07e@posting.google.com...
This TV does not start up; it has standby light on but no voltages are
present on the secondary of the smps transformer.
I have so far replaced leaky caps and tested for other faulty parts
but all is clear, except offcourse it doesn't run.
I suspect the power regulator STR58041 is playing up; Before replacing
it I would like to be sure that I checked it properly.
Any advice on this point:
the schematic shows that 0.4 v should be at pin 2 (base drive) and my
uncertainty is whether this can only be measured on powering on or it
should be there continuosly. I understand this voltage would cause the
regulator to start the power supply alltogether.
I hope expertise comes my way on this troublesome repair.
Thanks
Jim
 

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