42LG60 powering up problems

[anna1980]

I just got some problems with my 42LG60 and I cant seem to find the problem
When plugged in (after not using it some time) it turns on. Backlight turns on and image shows up. When turning it off and on. Nothing happens. It looks like some kind of reboot loop (red ring/white ring)

so I took the service manual.
Powerboard check ( EAY41971801 )
Step 1. Check 5v line. Check okay
Step 2. I connected a 10k resistor to 5v and power and checked the 5v, 12v and 16.5 v
the 5v line is okay; so is the 12v line
But the 16,5v line is low, about 14.68V

Step 2. Connecting a jumper wire for the backlight.
According to the servicemanual the backlight should turn on/off 4 times and than quit. Mines keep on blinking.
16v keeps jumping from 10-14 volts and the 12v lines jumps from 11-12

When disconnecting the jumper wire. The voltages keep jumping.

I already replaced the caps on de powerboard but that doesn't seem to help

[ReeceyBurger123]

Re: 42LG60 powering up problems

Heat Psu see if it helps the issue.

[anna1980]

Re: 42LG60 powering up problems

Heat Psu see if it helps the issue.

You mean the entire powerboard, or just parts of it
Before replace the caps on the right side I heated them with a hairdryer. But that didn't seem to work

[dick_barton]

Re: 42LG60 powering up problems

Does it say on the PSU board what current the 16V line supplies and if so could you load it up and see if it still jumps around and if so I would suspect the PSU. Just a thought.

[anna1980]

Re: 42LG60 powering up problems

Does it say on the PSU board what current the 16V line supplies and if so could you load it up and see if it still jumps around and if so I would suspect the PSU. Just a thought.

Yes I tried meassuring the current. It really jumps up and down.
But in this case the tv would start

But I could have done it wrong. When the TV started fine :

multimeter red probe on the 16v line
black probe on the chassis.

Sometime sparks were flying between the black probe and the chassis.
Ofcourse the tv reboots at that moment

[anna1980]

Re: 42LG60 powering up problems

Heat Psu see if it helps the issue.

I have noticed something weird.
When heating the entire psu, the tv doesn't reboot or between the reboots there is more time. But also the backlight/sound doesn't come on.
The ledring just lights up white

[Diah]

Re: 42LG60 powering up problems

since you have PS ON and PWB working , just delay at boot loop, its not PWB,

try to reset the TV to default Factory and check if it make delay again, also if there any update to firmware do it.

also read page 17 at Service M. if you have one voltage more or less than its will delay and effect on image start.

[anna1980]

Re: 42LG60 powering up problems

@Diah.

Vielen Dank für Ihre Hilfe (thank you very much) I feel really stupid but when I updated the software and gave it a factory reset everything worked. Ofcourse changing the capacitors isn't bad anyway but your solution seems te be the answer

[dick_barton]

Re: 42LG60 powering up problems

Sound like good news. Well done Diah,