CMOS Error Checksum 502 invalid

[Utente_IT]

Hi everyone.

For about 1 WEEK I have had this problem: CMOS Reset (502) invalid error message. If restarted seems to operate normally, unless it lost all power. (Shutting down PC with power supply still hooked up did not allow error to pop up.)

The exact All-in-One PC product is 24-df0068NL.

Warranty expired. Every BIOS recovery link fails.

Can you help me? Thank you.

[Paul_Tikkanen]

Hi:

From what you are describing, you may need to replace the coin cell battery on the motherboard that maintains the CMOS settings.

I'm surprised that is happening so soon.

I can't find a service manual for your PC.

This video may be of help, but I can't say for sure.

Removing & Replacing Parts | HP 22, 24 and 27 All-in-One PCs | HP Computer Service | @HPSupport - Yo...

Removing the CMOS battery is the last procedure on the video.

It appears that the battery is the standard CR2032 coin cell battery used in most PC's.

[Utente_IT]

That's right, the 2032 battery is ok. I ran the HW tests, and the pc is 2 1/2 years old.

The problem only occurs when I completely disconnect POWER LINE to the PC, if it stays connected with the green light on the back the problem doesn't exist even after 2 days without turning it on.

But I can't find an active link to BIOS drivers or fix for this model.

[Paul_Tikkanen]

Hi:

The product specs for your PC indicate that it comes with the 'Trout' motherboard.

HP All-in-One - 24-df0068nl Caratteristiche tecniche del prodotto | Assistenza clienti HP®

According to the motherboard specs, the Trout motherboard has a SSID of 87A4.

PC desktop HP - Specifiche della scheda madre Trout | Assistenza clienti HP®

This would be the latest BIOS update HP has for that motherboard SSID:

Driver - PC HP All-in-One 24-df0000i (7US89AV) | Assistenza clienti HP®

The rest of the drivers for the model series can be found at the link below:

PC HP All-in-One 24-df0000i (7US89AV) Download di software e driver | Assistenza clienti HP®

[Utente_IT]

Many thanks for your links in italian 🙂 

I downloaded and installed the latest BIOS for my mothrboard.. but nothing. If I remove total power line... checksum error continues 😕

[Paul_Tikkanen]

You're very welcome.

Unfortunately, I don't have any other suggestions for you to try other than to replace the CMOS battery and that would take a lot of work for no guarantee it would fix the problem.

[Utente_IT]

Thanks, I will replace a new CR2032 tonight... 

then I will write here 🙂

[Paul_Tikkanen]

I hope it works.

From what you are describing, it should.

I had the same issue with an old HP dc7900 SFF desktop PC.

I could leave it completely shut down and plugged in and it maintained the CMOS settings.

But if I unplugged it, I lost the settings.

I did it a few times and then decided to replace the coin cell battery and now it works fine, plugged in or unplugged, and reconnected to electricity.

The thing I don't understand is why the battery would go dead after only a 2 - 3 years.

I figured the battery would last much longer than that.

[Utente_IT]

 Infact....

Unfortunately not even changing the coin battery solved the problem. 😞

[Paul_Tikkanen]

I can't imagine what the problem could be.