820-01958-a NO BACKLIGHT

[NIKHIL@1997]

IN DIODE mode value

PPVOUT_S0_LCDBKLT_F

showing 0.020(with lcd and without lcd also same)
there is no sign of water damage ..

in voltage mode

PPVOUT_S0_LCDBKLT_F

0 v

PPVIN_S0SW_LCDBKLT_F

have 12.6 v(with lcd)

 

[2informaticos]

Strange to get 0.020 diode mode on a power rail which still can get 12.6V.
Remove power, discharge the remanent voltage; then check in diode mode again.

However, 12.6v there means Q8401 doesn't work; probably not controlled by U8400.
Did you try known good LCD assembly?

 

[NIKHIL@1997]

hi...i already purchased new lcd...but same backlight issue

 

[NIKHIL@1997]

again i will update the status and the voltages active on backlight section

 

[NIKHIL@1997]

PPVOUT_S0_LCDBKLT_F

0.020 on diode mode impedence(with and without lcd also same impedence)

with and without lcd also 0 v (i think before i give wrong info)

PPVIN_SW_LCDBKLT_SW

gets 12.6 v

 

[2informaticos]

OK, so your problem is between D8410 and J8500.
D8410 must be also bad; else, it can't have 12.6V on anode and 0V on cathode.
Remove L8420 and check where the low resistance remains.
One of the 2.2uF/100V ceramic capacitors should be bad.