lg 32lv375s no backlight no picture

[nbdy]

Hi

I have checked the power board (no desoldering), and everything seems to be OK ...

Anyone have a schematic of this board (EAX62865601/7) ?

Or anyone knows how to solve it ?

Btw. what pins do I have to short to power up the board (PWR-ON with 24 or GND) ?

thx

[Hamie]

Re: lg 32lv375s no backlight no picture

Photos might help.

[ReeceyBurger123]

Re: lg 32lv375s no backlight no picture

Photos and have you even checked the voltages labeled on the connector ?

[nbdy]

Re: lg 32lv375s no backlight no picture

With what to connect the pwt-on

[nbdy]

Re: lg 32lv375s no backlight no picture

Sorry,was on a bussines trip ...

here are the pictures :

http://s1.postimg.org/3jnllwoa7/20151205_125710_1.jpg

http://s24.postimg.org/nojsueoad/20151205_125719_1.jpg

http://s4.postimg.org/51cw75hal/20151205_125730_1.jpg

http://s8.postimg.org/v41u9om45/20151205_125817_1.jpg

This are all 4 boards on the TV

[nbdy]

Re: lg 32lv375s no backlight no picture

Hello,was on a long work out of home ...

Checked the voltages,have 3.5V,but 12V and 24V not

btw. the board looks ok like on the pictures no brown fluid around caps

thx

[nbdy]

Re: lg 32lv375s no backlight no picture

Rechecked the K10A60D, all ok with esr tester

anyone an idea ??

[CapLeaker]

Re: lg 32lv375s no backlight no picture

First we need to know the DC voltages measured on the connectors of the power supply bottom right. Check if the power supply is getting turned on by the main board (PSon pin). Measure the pins and post voltages with corresponding pin names.
If you have PSon and BLon, but no high voltage on the main filter caps, you either have a short in the secondary or the PFC isn't working.
To check if the PFC is working, measure the DC voltage directly at the main filter cap. It should be around handy 400V. Be careful!
No boosted voltage, no 12 / 24V.
To fire up the PSU, take a 1k ohm resistor and jump between STBY voltage and PSon. Same thing for BLon.

[nbdy]

Re: lg 32lv375s no backlight no picture

Sorry my work is on field outside my home,so can not reply over week ...

I mesure only the 3.5V on the white connector

the 24V is not present

PWR-ON is zero

BL-ON could not find on the board

where to measure on the main filter ???

thx

[dick_barton]

Re: lg 32lv375s no backlight no picture

Can you supply a closeup picture of the blue and white connector and the text written alongside giving the pinouts.

[i_am_hacked]

Re: lg 32lv375s no backlight no picture

Hi everyone friends i am new to here and i want to learn about schematics how to check on voltage and find the problem please help me i have experience in hardware but no experience on pdf schematic who to troubleshot Thanks for everyone ...

[nbdy]

Re: lg 32lv375s no backlight no picture

http://postimg.org/image/5g2fw39mh/

rechecked the block capacitors,all OK,but the gretz don't have any voltage on middle pins,and side pins

[dick_barton]

Re: lg 32lv375s no backlight no picture

Disconnect the white connector and check the power supply by connecting a 1K resistor from Power-On to 3.3V on the power supply white connector and check for 12V & 24V

[nbdy]

Re: lg 32lv375s no backlight no picture

With 1k resistor i have 12V and 24V on the pins and the 3.5V

[dick_barton]

Re: lg 32lv375s no backlight no picture

Remove the Power On pin carefully from the connector and plug the white connector back into the socket. Connect the loose wire to the 1K and connect to the 3.3V and check your backlights.

[nbdy]

Re: lg 32lv375s no backlight no picture

Still no backlight/no picture

the power led goes red,when i press ON the led flashes red and goes to orange

Could it be some other board,not the power supply

[Diah]

Re: lg 32lv375s no backlight no picture

is this your TV chassis LD12B main board EAX63557704 ?

if yes then its not power supply, its main board which cant repair, only replacement

[nbdy]

Re: lg 32lv375s no backlight no picture

Yes it is

thx for reply

[Diah]

Re: lg 32lv375s no backlight no picture

you can try also,this but not always work.

take the black heat sink out, so you will have access to the DDR and processor , heat them with hotair gun on 350 degree for round 10 second.

good luck

[dick_barton]

Re: lg 32lv375s no backlight no picture

It does appear to be a main board problem as Diah indicates. I suppose you have nothing to lose to try and heat it as suggested.