Thursday, January 08, 2015

VINVERTH VH32A5 - LCD TV - My Service Experience - Today the 8th Jan:2015

Vinverth VH32A5 - LCD TV - Dead set_Liquid spilled inside.
Faults occurred.
> Fuse blown [4Amp 250v]
> MOSFET5N50C at the main power regulator board [SMPS] damaged.
SMPS PWB _ FSP180-4H02
Main DIGITAL BOARD_ TM30G-V1.0
  Before replacing the fuse with an other, checked all the other components at the SMPS board for further damage.  Nothing fount abnormal, except a short circuit at the DC [rectified] voltage noticed. Soldered out the switching MOSFET 5N50C.  No short circuit measured.  On checking, the plastic body of the MOSFET has burned out and carbon particles accumulated there, causing a conduction path through the fixing screw to the heat sink metal; at the screw point.  I've illustrated the damage occurred to MOSFET in detail here.  Very rare fault indeed.  Might be of arcing due to water spill inside the set; I assume.  Replaced the MOSFET with a new one, no short circuit detected, inserted the fuse, switched the set On; OK.
See the component location and occurred damage to it
Damage to the component.
Click on the pictures to Zoom In