LG 47LE5300 Turns on but no picture, no sound

[bkamali]

Hi,
My LG 47LE5300 Turns on but no picture, no sound.
I am looking for PSU (YP47LPBD) schematic diagram as I think high voltage Mosfets are not working.
They are ice cold which tells me they are not working. Maybe the problem is the High-voltage resonant controller is not functioning.
Thanks in advance

[CapLeaker]

Re: LG 47LE5300 Turns on but no picture, no sound

We need to see pics. You need to invest into a DMM and measure some voltages. BTW, I'd leave my fingers off the primary side (to measure temperature) as that could end up deadly.

[budm]

Re: LG 47LE5300 Turns on but no picture, no sound

That heatsink is for the LED backlights and other power supplies is not going to do anything until you find out if the standby power supply is working not, if the PFC Voltage booster is working or not, etc. Do you have PS-ON, BL-ON, etc?
So show us the pictures of the whole back side of the TV so we can see what we are dealing with.
What DCV do you get at the black connector on the power supply board that goes back to the main board, there are labels for each one of the pin of that connector.
List the pin number with the name of the pin with the DCV readings when TV is plugged in but power switch is not activated, then with the power switch is activated.

[bkamali]

Re: LG 47LE5300 Turns on but no picture, no sound

Thanks a lot for reply.
Here are the pictures of TV and black connector pin voltages.

When you say: "PS-ON, BL-ON" what does it mean?
PS-ON=Power Supply On?
BL-ON=?

[budm]

Re: LG 47LE5300 Turns on but no picture, no sound

PS-ON = Power supply on, it is the command signal from the main board to turn on the rest of the power supply.
BL-ON (or Inverter ON) = Backlights ON for turning on the backlights circuits, the command signal is also from the main board.
You should read my BASIC LCD TV troubleshooting guide, your TV uses LEDs in stead of CCFL.

[bkamali]

Re: LG 47LE5300 Turns on but no picture, no sound

I checked the voltages.
The only voltage that I have is 3.3 V Standby. I do not have other voltages like 12 and 20 VDC.
Seems no command is coming from processor to start the system.
Any suggestions?

[andie]

Re: LG 47LE5300 Turns on but no picture, no sound

Dear All

I have problem my 47LE5300 has screened as below. Any solutions to check?
I'm new in repairing...LED TV

[andie]

Re: LG 47LE5300 Turns on but no picture, no sound

Sorry...
this is the picture... my mistake convert to pdf.
again...
my LED problems is the screen is showing as this picture..
could you help me what can I do?

I'm newbie

TV Type : 47LE5300

Tx

[newtothis]

Re: LG 47LE5300 Turns on but no picture, no sound

Looks like bad BGA symptoms.

I would say the mainboard is shot. Wait for others opinions too

[andie]

Re: LG 47LE5300 Turns on but no picture, no sound



it means i have to change main board? Micom?