820-00165

[Neil250]

Board chimes, fan spins
no display

L8304 black and cracked in half
replaced it..still no display
now 3.3V for 1-2 seconds measured at pin 2 after power applied

R8364 look a little worn so replaced it
lvds J8300 connector looks good
no water damage

usb mouse lights up
1.8V at cpu inductors

 

[2informaticos]

Check R8360.
Do you get 2.5V there at same time with 3V at L8304?

 

[Neil250]

2.67V at r8360

F7700 measures OL across it
it should be continuous no? like ~0.3ohms
8.67V at pin 1 ...0.30 at pin 2 of the fuse

fuse is blown?
that would explain the cracked inductor

i just can’t believe that is it

i checked 10 times to be sure
i don’t get an image-at least one I can see or a backlight

 

[2informaticos]

Replace fuse and check for shorts to ground on both pins of D7701; w/ and w/o LCD connected.
However, the big problem is missing voltage at pins 18/19 of J8300.

"2.67V at r8360"
Both pins?
If DP_INT_HPD goes high, PCH should recognize LCD correctly.

Check R8361/62 and pull down resistors from DP_INT lines.

 

[Neil250]

Changed fuse.
Checked diode.
Checked resistors indicated above.

Connected machine.
Machine now boots to LCD.

Solved!

Thanks informaticos!!