820-00840 - fan spin. touchpad working. no image/backlight.


does fan spin. touchpad working.No image, No backlight. No external display, USB light up but no flashing activity.

PP3v3_G3H 3.4v
vcore 0.9v
ppbus 13v
all_sys_pwrgd 3.2v
3V3_S5 3.3v
PP1V8_S5G 1.8v
pp20v 20v

minor corrosion on Q7670, u5460 area.
oh burnt caps next to u3100,
but its giving 20v on both ports, so i doubt these are the problem.
the clock signal is working, it's giving 24MHz since the vcore is present.
I've already tried donor board bios for testing.

inb4 dead CPU, sounds like it's not POSTing properly :(


New member
Yeah this sounds like an RIP to me if liquid was near the CPU forget it. If not, maybe try BIOS? I?ve had no luck with this symptom on the new ones


Staff member
You can pick them from older boards, like 3332/3476/4924, etc.
If for some reason LED circuit is not closed, you can get 55V aprox on backlight output.

A capacitor with 50V nominal should support such voltage, theoretically...