LG Power Board EAY60803201 (YP42LPBL) from 42LE5300

[lucky13]

Hello all,

I followed this thread

https://www.badcaps.net/forum/showthread.php?t=57647

and it apparently was a capacitor C114 (per BUDM) that caused the problem.

Here is my situation:

LG Power Board EAY60803201 (YP42LPBL)

ShopJimmy pix:
http://www.shopjimmy.com/lg-eay60803...upply-unit.htm

TV only has standby LED. I recll it also makes clicking sound when try to power up.

Found the power board only has standby voltage of 3.5v.

Removed power board from TV and jumpered the standby pin to power on pin as instructed by the training manual found on web.

P201 has 3.5V on pins 9,10,11,12.

However, no 12V on pins 17,19 & 21.

No, 20V on pins 2,3 & 4.

When I unplug the AC cord, the relay can be heard to click off after a few seconds.

Checked all fuses, diodes, heatsinked FETs on compoent side. Nothing wrong.

Here are some DC voltage readings:

Caps Standby Forced on by jumper
C511 (4.7u/400V) 165V 371V
C618 (22uF/450V) 0V 372V

C246,C247 0V 0V
C245,C244 0V 0V

This one uses a Viper27H (IC501). IC does not appear to be shorted/blown. Found 370V appears on the Drain (pins 7&8) (-ve lead on pin1) but drops quickly down. Vdd has 14.25V.

So I am not familair with SMPS and have found the datasheet for the Viper27H. Anyone can point me where to check next?

[Andrew F. Ali]

Re: LG Power Board EAY60803201 (YP42LPBL) from 42LE5300

There should be a BL-ON pin also that must be jumpered from the St-By together with the PS-ON pin.....

[lucky13]

Re: LG Power Board EAY60803201 (YP42LPBL) from 42LE5300

Sorry, I was not clear in my post.

The LG training manual had two steps.

1st step is PS Board Low Voltage Test1. Just jumper Standby to Pwr on and check for 12V and 20V. This board already failed at this step.

2nd step is PS Backlights Test2. You are right about the 2nd jumper from Standby to Inv-On. Of course it failed since I don't have 12V and 20V even.

In any case, I have both jumpers on while I measured these voltages.