Prima LC-32R25

[ve3tjd]

Morning guys:

I just picked up a Prima LC-32R25 LCD TV (garage sale). The past owner
said
the unit had no picture or sound. After pluggin it in, I notice that
the back-light
comes on, but no video or sound.

I've disassembled the unit and have checked the SMPS and all of the
secondary
regulators on all the boards.They are all where they should be, with
little or no
ripple.The only control that works is the "power" button.

Anyone have a schematic, or insight on what to check now? I've been a
tech
for 25 years but this is my first look at an LCD display!

Thanks,

Tedd, ve3tjd

 

[Mark Zacharias]

"ve3tjd" <tedd@ve3tjd.com> wrote in message
news:f5158e4f-c4f8-4ceb-abbb-13bd3a26f4b7@u1g2000vbb.googlegroups.com...

Morning guys:

I just picked up a Prima LC-32R25 LCD TV (garage sale). The past owner
said
the unit had no picture or sound. After pluggin it in, I notice that
the back-light
comes on, but no video or sound.

I've disassembled the unit and have checked the SMPS and all of the
secondary
regulators on all the boards.They are all where they should be, with
little or no
ripple.The only control that works is the "power" button.

Anyone have a schematic, or insight on what to check now? I've been a
tech
for 25 years but this is my first look at an LCD display!

Thanks,

Tedd, ve3tjd

Look for high ESR capacitors or shorted rectifiers in the smps power supply.
Probably not much else you can do. If you should find a shorted rectifier,
be sure to use a fast recovery type suitable for switchers. These will
usually show a lower forward resistance on a DMM diode-check function.

Mark Z.