LG 55LF 5800 no video,no sound or backlight

[Davi.p]

My bet is as usual some of the BGA that are bad to resolder, especially with LG is an old habit, does the s.b. led glow two times short and then stays lit long? Why did you changed the b.l. led? what's the story of this set? is it been left sitting for long in a moist ambient? bye..

[waybel]

My bet is as usual some of the BGA that are bad to resolder, especially with LG is an old habit, does the s.b. led glow two times short and then stays lit long? Why did you changed the b.l. led? what's the story of this set? is it been left sitting for long in a moist ambient? bye..

Got it from a guy that bought it new .No the standby light powers on .Hit remote it blinks 3 times and goes out as it should.Changed the leds because some of the reflectors had fallen off so replaced strips while i had it apart .Looks like i need to find another main board

[lotas]

Have you tried warming up the processor or is your hair dryer not working?

[waybel]

I warmed it up 3 times with my hot air but no change

[lotas]

If you have nothing to lose, warm it up for more time, 3 minutes...

[waybel]

If you have nothing to lose, warm it up for more time, 3 minutes...

tried that also.If the processor wasn't working shouldn't it be cold?When the tv is turned on it is warm to the touch.Or could it be that some of it is not contacting but still works?

[Davi.p]

No good for me at this point to insist, a bad made reflow cannot resolve the case, maybe worsen, better to decide if making a reballing (of what? CPU, ram , emmc/nand, what? witch price?) or buy a main board tha could work but not last long.. mad technology of fool greed manufacturers

[lotas]

It should be hot when it is fully operational, which is why a radiator is installed...

[lotas]

Just looking quickly on various places on main board found 1.2 V 3.3V 3.5v 5v 12v and 24v

Are 1.8V and 2.5V power supply present or not?

[Davi.p]

easy to check: check every choke inductor resp. to gnd, except the 4 around the audio ic..

[Diah]

check the MICOM !C3000 pin 4 did exist >3.3V ?

[waybel]

check the MICOM !C3000 pin 4 did exist >3.3V ?

pin 4 is 2.1 volts

[lotas]

It will be there, since there is 12V on the T-con.

[Diah]

its remain low.. no juice enough

try to disconecct this rail from IC and other side of the rail fed it with 3.3V

[Diah]

It will be there, since there is 12V on the T-con.

this is DRV_ON another rail switching T-CON 12V

[lotas]

this is DRV_ON another rail switching T-CON 12V

Why blow something, there is 12V on the T-con!

[Diah]

Why blow something, there is 12V on the T-con!

1- PANEL_CTL 3,4 Normal... he have 2..1 i wrote no more juice more
2- i wrote disconnect Pin 4 from the rail... read again... the other side of the rail will be provided with 3.3V
MICOM will never hurt at all

[Diah]

if the rail of 3.3V we are going to use will drop down again to 2.1V we will have ours hand on the reason

[waybel]

So you want me to unsolder pin 4 ?

[Diah]

So you want me to unsolder pin 4 ?

yes, but if you follow the pin 4 rail you will finnd easy point to separated the pin. post clear photo on the area of the PIN 4 rail.. we dont want you harm the MICOM chip