LG Led TV 32LN5300UB Completely Dead

[ivtec]

Hi guys i found the Lg tv in the curve completely dead, checked power Supply board and no voltages anywhere,no volts in the primary side or secondary side,no volts 3.5v,24v,12v,i checked mosfet q101 and is good,fuses are all good also checked all components that i could check with my fluke and cap analyzer and all seems to be in order,so it seems to be a mystery . Any help will be appreciated to save this tv from landfill.

[ivtec]

Re: LG Led TV 32LN5300UB Completely Dead

Also i get 87v only 'see attachment pic

[ivtec]

Re: LG Led TV 32LN5300UB Completely Dead

Also i only see 87v from AC input to fuse?

[R_J]

Re: LG Led TV 32LN5300UB Completely Dead

What was the meter set to? AC or DC? Looking at your last picture you are checking the voltage between the fuse and ground. You need to check the AC voltage across Line and Neutral. Not Line and Ground

Just check the DC voltage ACROSS the main filter capacitor. It should be 160vDC. Then with the board un plugged from ac, check the resistance of R113, it should be about 0.15Ω
When checking voltages in the Primary, you must reference HOT Ground (C110 negative leg)

[ivtec]

Re: LG Led TV 32LN5300UB Completely Dead

What was the meter set to? AC or DC? Looking at your last picture you are checking the voltage between the fuse and ground. You need to check the AC voltage across Line and Neutral. Not Line and Ground

Just check the DC voltage ACROSS the main filter capacitor. It should be 160vDC. Then with the board un plugged from ac, check the resistance of R113, it should be about 0.15Ω
When checking voltages in the Primary, you must reference HOT Ground (C110 negative leg)

Thanks R_J for correcting me, long time i do not repair anything and getting old and forgetting ; Ac Line and Neutral =122v AC, Neutral and fuse=122v Ac, across filter Cap C110=169v Dc. Resistance across R113=0.4ohms, appreciate your help.I took all those voltages without Power supply being connected to main board and panel?

[R_J]

Re: LG Led TV 32LN5300UB Completely Dead

Are you sure you don't have 3.5v on the secondary side?

[ivtec]

Re: LG Led TV 32LN5300UB Completely Dead

Are you sure you don't have 3.5v on the secondary side?

hI R_J you are not believe it,i picked up this tv from the curve and it had no power cord ,but i had 3 cords in my scrap and took one to the cellar where i have the tv ,but the cord was bad ,the volts i gave you were taken with just power board connected with another cord ,i took this good cord to the celler and now when i connect the cord it goes to standby with red led ,when i power it up it gets a high loud sound from the tuner i guess, but with no display back light, and i tested volts going to the main i get the 3,5v, 12, 24v,i think the main board is bad!