55ln620v LG flash then no backlight

[wreksta]

as above took set apart down to leds all leds light using
multi meter
any ideas what I should check
next please
cam test voltage from led connector on power board ?

[Diah]

Re: 55ln620v LG flash then no backlight

as you take the LCD apart, you can start your LG with out Panel, then with eyes at start up you will find that one or more LED wont light on. this best way to you narrow which LED Fault at start up

[zomi]

Re: 55ln620v LG flash then no backlight

test the leds
check the connectors sometimes these go faulty, hard wire connectors..

if any failing led found
best to buy a full set of new strips.

[budm]

Re: 55ln620v LG flash then no backlight

You need to upload good clear pictures of the whole backside of the TV showing all the boards and also good clear straight shot of the top and bottom side of the power supply/LED driver board.

[wreksta]

Re: 55ln620v LG flash then no backlight

hi all I've tested all the leds I've even swapped power supply with a known working one and logo flashes then no light so I'm thinking main board
is there a fix for the main board

thanks I'll upload voltages soon

[wreksta]

Re: 55ln620v LG flash then no backlight

hi there just an update
led+ volts shoot to 125v dropping to 82
led- volts shoot to 42v dropping to 5v
same for the other 2 + /-
both same on two power boards
all leds light with tester even individualy

[zomi]

Re: 55ln620v LG flash then no backlight

Jump all the connectors directly with wire

is not an issue with mainboard.

[wreksta]

Re: 55ln620v LG flash then no backlight

which connectors mate thanks

[zomi]

Re: 55ln620v LG flash then no backlight

where the 2 strips connect together hard wire those.

and also maybe the whole wiring harness

its either an issue with the wiring
or a failing led that is not showing up with the led tester as its not supply enough current.

[budm]

Re: 55ln620v LG flash then no backlight

Can you verify the model number of the TV?

[wreksta]

Re: 55ln620v LG flash then no backlight

yes it's LG 55la620v

[wreksta]

Re: 55ln620v LG flash then no backlight

bottom 3 rows flash top 4 don't
I've checked all condunity for all connectors and test good
could it still be faulty?

[zomi]

Re: 55ln620v LG flash then no backlight

check resistance between all points.
look for any with high resistance


and u have tested all leds and they have tested good ? thats correct yeh ?