CMOS Reset (502) The CMOS checksum is invalid - Screen flashes for a second before going off.

[zozazer]

I have a HP Pavilion - 13-an1007na that I have been trying to get work. It doesn't even seem to get to the bois. When I booted it the first time I got an error "CMOS Reset (502) The CMOS checksum is invalid" which asked for a reboot. I said yes to the reboot and then the screen went black. 

It now seems to turn on and the screen lights up for a second before going fully black again. If I leave it then it will keep repeating this forever with it lighting up for a second. No text shows after this. I think it is trying to check the bios and failing.

I have tried removing the battery and running it on just the charger but it has the same error.

This model doesn't appear to have a CMOS battery so I can't replace that and I don't have a replacement for the main battery.

Is there anything else that could be causing the issue?

[erico]

Hold down the Windows key and the B key at the same time.

Press the power button while holding those two  keys down until the notebook responds with a "recovering the BIOS" message. I paraphrased that as I don't remember the exact message.

You may have to hold the keys down for almost a minute before the laptop responds.

[zozazer]

Thanks for the quick response. I have tried that using a Recovery USB with the latest BIOS update and it seemed to run through okay however when it finished it came up saying "a system bios recovery has occurred error 500" and then after another reboot it is now back to doing the same thing as before.

It looked promising for a bit.

[zozazer]

I did a bit more testing and found out the below:

When I take the SSD out it errors saying to harddrive found and then let me go to System Diagnostics.

Power check - Passed

Memory check - Passed

Board check- Passed

Storage - Not attempted

Keyboard - Passed

I'm wondering if it is the SSD that is faulty but I don't know of anyway to test this without another SSD that fits. Which I don't have.

[erico]

BIOS issues and storage devices are not related in terms of BIOS errors.

What you tried is not what I suggested. A BIOS recovery is as I described in my earlier reply.

With any Windows PC, the result of removing the hard disk or SSD will produce the hard drive not found error message.

It is normal and means nothing in this case. All it is saying is that it can't find the SSD that you removed, which makes perfect sense.

If you look at the SSD it will give a brand name.

All hard disk and SSD manufacturers produce utilities that will enable you to use the S.M.A.R.T reporting system to see the health of an SSD.

[zozazer]

Hi Erico,

I did try the Bios recovery as I said in my previous message. It ran through and looked successful, then rebooted as part of it and went back to a black screen.

I only brought up removing the SSD to show that the hardware checks came back as passed for everything else. 

[erico]

I would try to update the BIOS again.

If it fails, there is the possibility that the BIOS chip is faulty, causing it to not retain data.

[zozazer]

I tried it a couple of times again and I can't even get the BIOS recovery to show now. If the BIOS chip is faulty does that mean the board needs to be replaced?

[erico]

No.

There are PC/Laptop shops in the UK that can replace the BIOS chip for you.

You can contact YouTuber Adamant IT at his shop in Shaftesbury,UK. He does down to component repair of desktop and laptop PCs..

https://www.google.com/maps/place/Adamant+IT/@51.0061283,-2.1940847,17z/data=!3m1!4b1!4m6!3m5!1s0x48...

[zozazer]

I've just got home and tried the BIOS recovery USB again and it ran through, I think successfully. It the went to a a black screen with the fans spinning up loudly before stopping. The fans then spin up again and it repeats going quiet and then fans loud. 

The screen never does anything and there are no lights apart from the power.