Sharp model LC26DV20U totally dead
 

I need your help once again group. This is my first LCD TV to fool
with, but I suspect troubleshooting the power supply is the same. The
set has no standby power, totally dead. I did some initial checking in
the supply, but found nothing wrong. Have good B+ on the switching
regulator, but even trying to trace the PCB, I can't figure out where
the standby power is derived. I have checked almost every component on
the PSB and found nothing bad. So, without a schematic, I was hoping
someone here has dealt with this type issue on same model or similiar.
It's a friends TV and only 6 months old, but he asked me to look at it
before doing the warranty thing - story that I didn't want to get
details on since it was going to cost him money ($225) to ship for
repair. Thanks to all that reply, and yes, if it was my TV, I wouldn't
be paying jack, but as I said, I would rather just help him with
repairing it. Thanks again group.

Sharp model LC26DV20U totally dead
 

On Mon, 14 Jul 2008 15:51:56 -0700 (PDT), put finger
to keyboard and composed:

I need your help once again group. This is my first LCD TV to fool
with, but I suspect troubleshooting the power supply is the same. The
set has no standby power, totally dead. I did some initial checking in
the supply, but found nothing wrong. Have good B+ on the switching
regulator, but even trying to trace the PCB, I can't figure out where
the standby power is derived. I have checked almost every component on
the PSB and found nothing bad. So, without a schematic, I was hoping
someone here has dealt with this type issue on same model or similiar.
It's a friends TV and only 6 months old, but he asked me to look at it
before doing the warranty thing - story that I didn't want to get
details on since it was going to cost him money ($225) to ship for
repair. Thanks to all that reply, and yes, if it was my TV, I wouldn't
be paying jack, but as I said, I would rather just help him with
repairing it. Thanks again group.

I suggest you upload a photo of the PSU/PCB to your web space.

Otherwise, locate a +5V or +3.3V point somewhere in the logic (at the
main CPU?) and trace it back to your PSU.

When I'm unable to obtain circuit diagrams, I attempt to find the
datasheets for the various ICs. Sometimes these will contain
application circuits.

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