HP Pavilion Flashing Power Light loop

[DiamondTech61]

Hi Guys, I have a HP Pavilion laptop 15-dk1007na that wont stay on, when power on the power light flashes on for about 5 seconds then off for about 3 and it keeps looping. The screen does go darker when on while it is powered. I have tested with new RAM in each slot. I also disconnected the battery and the laptop took longer to POST but did show a CMOW reset error and the light stayed on till I pressed enter to reset then it went back to the same problem. I have also booted with an HP Recovery firmware on a USB stick but that didnt seem to load. Board number is GPC52 LA-J641P REV 1.0

[mon2]

Re: HP Pavilion Flashing Power Light loop

CMOW reset error

CMOS reset error.

Are you using the original power adapter recommended for this laptop ?

Start with checking the voltage @ the DCin connector. Is this voltage present at all times ?

Near this connector should be the usual DCin x 2 mosfets that act like solid state switches. These mosfets are driven by a local battery charging IC and is often from TI (former BenchmarQ) with a marking of 'BQ' something.

Locate these parts and post their top side markings. From the IC markings, we can guesstimate what you have in front of you.

Often the mosfets are to blame but your case may be different - perhaps a failed capacitor which acts like a short -> causes the current loop circuit to see a higher draw -> will force the local power rail to shut off.

Will be good to also review each (grey?) coil on your circuit board -> remove all power -> meter in resistance mode.

One meter probe to one side of the coil; other probe to ground. Record the resistance reading.

Each coil is linked to a local power supply rail. You are checking the resistance to ground to ideally locate a power rail that may have a shorted capacitor.

[sasser]

Re: HP Pavilion Flashing Power Light loop

im also got the same issue. maybe bios need to reflash.i can enter the bios menu after disconnect battery. but return problem after a few minute

[hpboy]

Re: HP Pavilion Flashing Power Light loop

Hi guys.. did you ever resolve this problem?

[hpboy]

Re: HP Pavilion Flashing Power Light loop

For anyone having this issue, here is the resolution. The issue relates to a corrupt BIOS which needs restoring.

Download the latest BIOS update from HP, create USB stick (using the HP utility in the BIOS download from HP)

Connect the USB stick to the laptop.

Power on the laptop and if you have this issue it will power on (led on power button) then as we know, the laptop constantly reboots.

After a reboot, as the power led switches off, press and hold Windows + B keys, keep holding them down and let the laptop power cycle

This time, it will boot into BIOS recovery mode, and install the BIOS from USB