LG 55LW5600 No Video No Sound

[nomoresonys]

Re: LG 55LW5600 No Video No Sound

List the panel number of the tv and we'll see what we can figure out.

[engyshe]

Re: LG 55LW5600 No Video No Sound

Tv model is 47LW5700
LA12C is assembly number
main board EAX64344102(1)

[nomoresonys]

Re: LG 55LW5600 No Video No Sound

Panel number should be on the back metal chassis on a sticker.

[engyshe]

Re: LG 55LW5600 No Video No Sound

I see. I will look when I get home. None of my pictures cought that detail.
I have been reading service and training manuals, but could not figure out how to determine if backlite diodes are fine if there is no mainboard 3.3V to supply TCON board and other controls. Unless it is this 220ohm to ground test. In that case, should I disconnect cables between main and TCON board (LVDS/power)?

[engyshe]

Re: LG 55LW5600 No Video No Sound

Here is the panel number LC470EUF (SD) (F2)

[nomoresonys]

Re: LG 55LW5600 No Video No Sound

This appears to be a good list of substitute mainboards for your 47 LW5700, might need to put LG in front of them if searching:

EBR73360903
EBR74261202
EBR74261207
EBT61409804
EBT61410005
EBT61804804
EBT61804905
EBT61804907
EBT61804912
EBT61804913

[nomoresonys]

Re: LG 55LW5600 No Video No Sound

Your best bet might be one of the repair services, I would try to get one that has a good rep. and offers at least a 6 month guarantee: https://www.ebay.com/sch/i.html?_fro...10008&_sacat=0

[engyshe]

Re: LG 55LW5600 No Video No Sound

I will contact repair shops and send my board out. I will verify that panel LEDS are fine first and then do that. Thank you for the help and your time. Cheers

[PeterKiryluk]

Re: LG 55LW5600 No Video No Sound

Just had a TV come in exactly as stated above No backlight, button turns from red to white stays white nothing showing on picture. Main board needed to be reheated. LG 55LW5600

[wylde]

Symptoms point to main board problem. Checking all the voltages and resistances is hard to understand for most non-electronics guys like me - best information that I found was this. If the LED lights / screen image is not coming up the power board is not necessarily the problem, if you have the power board transforming voltages that are readable on your outputs than it is probably ok even if they are not exactly to spec- the main board actually needs to signal the power board to supply voltage to backlight circuit.
Reflow repair on the mainboard is probably the best option- if you are doing it at home with a heat gun reduce the size of the tip as best you can, even with a tin can (wrap it around to make the tip the diameter of a finger) just do a test before attempting on the board by putting some solder on an old board/wood scrap and applying the heat until it melts - if you count the number of seconds it takes you will have a rough gauge as to how long to apply heat to your chip to melt the hidden solder .
You will need to remove the heatsinks (hardest part)that are on the chips. Try and protect surrounding area with alu tape/carboard etc to isolate the chip you are heating. As you focus the heat on the chip try not to move it or any other components - keep the blowing speed of your heat gun to a a minimum - there are tons of surrounding resistors etc that are tiny so be careful not to bump them or blow them out.

here is another thread that outlines similar problem to yours. https://www.badcaps.net/forum/troubl...-s-help-please