LG60PN5300 Not turning on

[doesntmind]

Attempting to repair an LG60PN5300 that displays standby light yet does not turn on when pressing the power switch

Standby readings:

pin# - Desc - Standby
1 - 17V - 17.2V
2 - 17v - 17.2V
3 - GND - 0V
4 - GND - 0V
5 - 5.2V - 5.3V
6 - 5.2V - 5.3V
7 - 5.2V - 5.3V
8 - VS_DET - 2.8v
9 - GND - 0V
10 - GND - 0V
11 - GND - 0V
12 - VS_ON - .67V
13 - 5.2V - 5.3V
14 - 17V_DET - 2.36V
15 - RL_ON - 1.25V
16 - AC_ON - 5.2V
17 - M_ON - .64V
18 - AUTO_GND - 4.2V

I tested the power switch and it appears to be fine

The main board is missing an HDMI port which broke off, i dont see any shorts on the contacts left behind

[doesntmind]

Re: LG60PN5300 Not turning on

forgot to attach photos

[doesntmind]

Re: LG60PN5300 Not turning on

bump

[freakaftr8]

Re: LG60PN5300 Not turning on

Sounds.like your mainboard has bricked. Have you tried jumpering 5v to ps_on? Also you can disconnect mainboard cable on this model I believe to have power supply rails come up.

[R_J]

Re: LG60PN5300 Not turning on

Does the Vs or Va voltage come up for a second then drop off?
Have you checked for shorted fets etc. on the y-sus and zsus boards, try disconnecting the cable going to the ysus and see if the Vs voltage comes up for a sec. on the power supply, if not try disconnecting the cable between the power supply & Zsus board and see if the Vs comes up fora second.
You could also have a bad upper or lower buffer board.
Check this thread https://www.badcaps.net/forum/showth...light=60PN5300 it might help

[doesntmind]

Re: LG60PN5300 Not turning on

Does the Vs or Va voltage come up for a second then drop off?
Have you checked for shorted fets etc. on the y-sus and zsus boards, try disconnecting the cable going to the ysus and see if the Vs voltage comes up for a sec. on the power supply, if not try disconnecting the cable between the power supply & Zsus board and see if the Vs comes up fora second.
You could also have a bad upper or lower buffer board.
Check this thread https://www.badcaps.net/forum/showth...light=60PN5300 it might help

The Vs pins read a steady 206V on zsus and ysus boards.
I've noticed the 15v pin on ysus was only reading 5v

[R_J]

Re: LG60PN5300 Not turning on

Looks like the 15 volts could be produced on the Ysus board, buffer board could be loading the 15v down to 5v
More info here https://www.badcaps.net/forum/showthread.php?t=45244
I see heatsinks on the buffer ic's, do any of them get warmer then the others?, I believe you can run the tv with either the upper or lower buffers removed, (do this for testing and only a short period of time)
disconnect the (upper) buffer board from the Ysus, also disconnect the ribbon connecting the upper & lower buffers, You can leave the buffers connected to the panel and don't need to disconnect them.
Try the tv and see if you get a picture on the lower half of the screen. if you do, the upper buffer is bad.
if not then unplug the tv, connect the upper buffer board back to the ysus and disconnect the the lower board and plug in and turn on the tv, see if there is a picture on the top half of the screen.

[doesntmind]

Re: LG60PN5300 Not turning on

Having the zsus board only connected to the power supply i still only read 5v on the 15v pin
I believe 15V is produced by the zsus

my reading on the connector that goes from main power supply to zsus reads
1 - VS - 206V
2 - VS - 206V
3 - NC - 0V
4 - GND - 0V
5 - GND - 0V
6 - VA - 55V
7 - M5V - 5.25v

[tom66]

Re: LG60PN5300 Not turning on

15V is most likely generated by Y board, actually... Using the yellow transformer onthe Y board.
If Vsc and -Vy are bad, then 15V may also be bad.