Norcent 42" Plasma TV

[Chris F.]

Someone recently brought in a Norcent PT4235 plasma TV. It had apparently
"just quit". When I plug it in, the relays click a couple of times like it's
trying to start, and a bit of static flashes on the screen, but that's it.
I looked under the back cover and didn't see any bulged or leaking caps,
nor did I find any obvious shorts in the many high-wattage transistors.
Before I go any further with this, I'd like to know if there are any known
issues that someone could point me to. This set has a massive number of
power supplies in it, and I really don't want to waste several hours on
something that may not be fixable in the first place. This is a very cheap
brand of set (retailed for just $700 new), so I doubt it's worth spending
much time on.
Thanks for any advice.

 

[Mark Zacharias]

"Chris F." <zappyman@hotmail.com> wrote in message
news:4bd87442$0$12464$9a566e8b@news.aliant.net...

Someone recently brought in a Norcent PT4235 plasma TV. It had apparently
"just quit". When I plug it in, the relays click a couple of times like
it's trying to start, and a bit of static flashes on the screen, but
that's it.
I looked under the back cover and didn't see any bulged or leaking caps,
nor did I find any obvious shorts in the many high-wattage transistors.
Before I go any further with this, I'd like to know if there are any known
issues that someone could point me to. This set has a massive number of
power supplies in it, and I really don't want to waste several hours on
something that may not be fixable in the first place. This is a very cheap
brand of set (retailed for just $700 new), so I doubt it's worth spending
much time on.
Thanks for any advice.

It's a slim shot, but you might try (when powered down) measuring resistance
from the output side of all voltage regulators and rectifiers looking for a
short to ground. (Often the rectifiers are TO-220 packages).
Saved my ass once recently. A Samsung plasma with power supply issues - and
the board no longer available from Samsung. Robbed a TO-220 rectifier of the
same type off a scrap board.

Mark Z.

 

On Wed, 28 Apr 2010 10:45:36 -0700, "Chris F." <zappyman@hotmail.com>
wrote:

Someone recently brought in a Norcent PT4235 plasma TV. It had apparently
"just quit". When I plug it in, the relays click a couple of times like it's
trying to start, and a bit of static flashes on the screen, but that's it.
I looked under the back cover and didn't see any bulged or leaking caps,
nor did I find any obvious shorts in the many high-wattage transistors.
Before I go any further with this, I'd like to know if there are any known
issues that someone could point me to. This set has a massive number of
power supplies in it, and I really don't want to waste several hours on
something that may not be fixable in the first place. This is a very cheap
brand of set (retailed for just $700 new), so I doubt it's worth spending
much time on.
Thanks for any advice.

A common cause of this problem is a shorted sustain card. This

appears to use an LG panel. One troubleshooting method on these
panels is to unplug the TV, disconnect the cable linking the power
supply to a sustain card, then plug the TV in again and see if the
power supply turns on. If that didn't help,disconnect the next
sustain card.

PlainBill