Fan starts then stops, no power, caps lock blinks slowly

Hi @jayeff ,

Thank you for the quick response, there is indeed a pattern. One slow blink, pause then repeat. I'll follow your steps now to see what else I can figure out and see if this helps me resolve the problem. Hopefully my next comment will be to advise the fix and say thanks.

Best

H

Hi @jayeff

Okay, so I am back again. Having followed through the various links you kindly sent, the conclusion is that the CPU has failed. When reviewing the main document, there does not seem to be a separate link for the CPU? The only code I can find is 858579-601, which is the Windows 10 motherboard with the i7-6500U chip.

On the HP Partsurfer website they want +£850 for this part. I only paid £500 for the PC.

I'll keep investigating, but open to further info or ideas.

Thank you

H

@hkuk2020 ,

The CPU is hard mounted on the motherboard that is why there is no replacement part specifically for it. The whole motherboard needs to be changed.

Last throw of the dice is to try a power refresh to check just in case the BIOS has been scrambled for whatever reason. It only takes a little while.

Disconnect the charger if connected, remove the main battery from the laptop, remove the RTC battery from the motherboard, (use the manual to view how to remove the RTC battery -p.63 and remember the orientation of the battery for when you go to put it back in, usually it is +ve on top). If you have a DMM (digital multimeter, check the voltage of the RTC battery while it is out. If it is <2.6V DC replace it with a new one. They're a common battery available most everywhere. Look for the battery number on the battery mostly they are CR2032 but it may be different. You can still put it back in if it is <2.6V but it will need to be replaced as if it is too low BIOS corruption can occur. The battery is non rechargeable and usually has a life of 5-7 years

Then press and hold the laptop's Power button for 30 seconds and then release the button to discharge any residual power from the motherboard and thereby restore the BIOS to default.

Reinsert the RTC battery, reinsert the main battery, connect and switch on the charger and try to turn on the laptop.

If still no good it is a motherboard problem.

Commiserations

If the part number you quoted is the one for your motherboard (look on the motherboard itself perhaps for the part number to verify) search online using the "part number only" to get other suppliers

@jayeff

Thank you for your help, I'll hopefully get around to trying this today.

After jayeff's steps you may want to take out HDD, reseat RAM, clean fan, etc.

Here's a YouTube video showing how to:

https://www.youtube.com/watch?v=ZGyD-ZJQ...

Quite well done, I thoght.

If the fan is really dirty or not spinning it could be the CPU over heated but I'm guessing HDD (especially if mechanical - I'd take the HDD out and connect to USB adapter and try on another computer)

or RAM defective or improperly seated - swopping around, etc. ????

Of course you didn't drop it. Right?

I think a corrupt BIOS is also a possibility.

https://support.hp.com/au-en/document/c0...

The USB recovery drive is a good step if all on the laptop is corrupted. . .

But you tried all that????

But have you tried it with the HDD taken out as HP says, "If HP BIOS Update does not display or the issue persists . . . there (could be) is a hard drive issue." Worth a try.

Good luck!