Attempting to repair HP 15-f387wm

[Grey Beard]

HP laptop charger light on, but won't turn on.
I have checked; charger - Good
19.6 volt path - Good thru all sub power supplies.
3.3 volt - Present at IO.
Tried Mobo in & out with nothing connected but - old then new, power button - Dead.
Stumped.

[stingerchamp]

Re: Attempting to repair HP 15-f387wm

HP laptop charger light on, but won't turn on.
I have checked; charger - Good
19.6 volt path - Good thru all sub power supplies.
3.3 volt - Present at IO.
Tried Mobo in & out with nothing connected but - old then new, power button - Dead.
Stumped.

Hi, is this dau99vmb6a0 rev a motherboard?


Dont listen to the Nay sayerssS

[Grey Beard]

Re: Attempting to repair HP 15-f387wm

Yes, it is the DAU99VMB6A0 Rev-A Mobo.

[stingerchamp]

Re: Attempting to repair HP 15-f387wm

Yes, it is the DAU99VMB6A0 Rev-A Mobo.

Hi ,

Do the hard reset and check

1-Push Power button on for the 20 sec while no charger plugin and after wait for 20 sec plugin and try to turn on the laptop .
2- remove accessories and remove battery and remove RTC battery and wait for 30min and then put it back and try to turn on with power charger plugin alone

[Grey Beard]

Re: Attempting to repair HP 15-f387wm

Sorry for the delay. I did as you suggested & still nothing.

[stingerchamp]

Re: Attempting to repair HP 15-f387wm

Do you have schematic for this motherboard?
Does laptop turn on with only battery connected?

Have you tried CMOS reset by holding
Win+ v with power button for 2 sec then release power button only but keep holding win+ v until CMOS is invalid option display on your screen. Reset bios

Do you have schematic so we look for fault using schematic.?

When you get schematic check AD_id pin voltage
If you have 90 watt charger it should be around 1.25
For 45w it is .47 Voltage. For 150 watt it should be around 2.5 , I am not sure for the 150 watt.

Check power button voltage it should be 3.3 before pressing and 0 after press/holding.

3 voltage rail is present or not, 5 voltage rail.

Check Suspend voltage ( not present)or always (present) before .

Do you have voltage on rtc cell it should be above 2.8 Vol.