LG TV - 44SZ21RD problem

[Matt - McC]

Hi,

I have a 44" LG 44SZ21RD TV which developed a fault yesterday after only 2 years of use.

For some reason it has strated turning itself off into standby mode for no reason.

If you leave it for 20 mins or so and put it back on you get between 30 mins to an hour before the same thing happens again. If you turn the TV straight back on it seems to happen again a lot quicker.

I wondered if there was an over heating problem or if the fan was faulty so I placed a cool air blower on the air intake to see if this helped but it doesn't seem to make a difference which makes me think it is maybe something other than over heating.

Any help or advice would be much a ppreciated

Cheers

Matt

[electric eel]

Problems with LG plasma tv PDP42V5 using DGK-420W ( DGK420W revA) power supply pcb.
This PSU is also used in a lot of other brands of plasma screens, and can give problems after 2 to 3 years of use.
My own problem... no picture, sound ok. Green LED on psu board flashing 6 times (5 x short 1 x long pulse) .
On turn on, relay pulls in, 5V DC ramping up OK, 65V DC (VA) ramping up ok, 190V DC (VS) starts to rise,then fails, relay

drops out, and fault LED comes on flashing, and 5V, 65V and all other supplies lost.
SOLUTION (for me).....
Capacitor "C97" 1uf 630V DC blown (stinking!) polypropylene capacitor 1uF 630V DC. (Also look for slight swelling of sides

on this type of capacitor indicates faulty capacitor).
Circuit diagram shows this capacitor as a 2.2uF 630V DC ??? wrong capacitor fitted at factory?.
Replaced capacitor with correct type 2.2uF 630V DC polypropylene ( note.. MUST use high specification type capacitor,

example.. WIMA type MKP10 specially designed for switch mode psu type applications).
Plasma TV is now working ok.

Other capacitor to suspect in case of PSU problems would be "C19" 1uF 630V DC polypropylene.

Resources..............

Similar Plasma tv which uses same PSU ....service manual pdf.....
http://www.belson.es/descargas/Esquemas%20Belson%20Chile/BSV-4251A%20SERVICE%20MANUAL.pdf

Circuit Diagram for DGK-420W psu board... pdf available at......
http://rolsen.ru/content/tech/POWER_Schematics.pdf


Lg Acadamy "secret" website for LG brand Plasma tv's.....

http://136.166.4.200/contents/Files/Displays/PDP/


I HOPE THIS INFORMATION IS OF HELP TO YOU, please feel free to pass it on to other help forums.
I you manage to fix your equipment with this info please email me to let me know I've been of some help at....
spamandeggs(at)tiscali.co.uk

Good Luck.

[gary]

LG 44SZ21RD IS AN LCD REAR PROJECTION TV, TRY RESOLDERINGTHE FLASH ROM IC2 ON THE VERTICALLY MOUNTED BOARD THAT HAS THE TUNER ON IT, THIS SEEMS TO BE A COMMON FAILING ON THIS SET, YOU WILL NEED A VERY FINE POINT SOLDERING IRON AND A STEADY HAND