Dead battery and BIOS issues

[Abdullah719]

Hello. I have a HP Omen 17 (2017) (an013tx) laptop. The warranty period for the product is over.

I bought it second-hand in perfect condition back in July this year. However, the battery suddenly died just around a month ago (last week of September). I didn't think much of it as I usually use the laptop with the charger connected, though I did intend to replace the battery going forward when possible. Unfortunately, the battery is not easily available in my country and I'd have to order it online.

Anyway, fast-forward one month later and yesterday I had a new problem to deal with. When I booted up the laptop yesterday, it gave a CMOS 502 reset error, followed by a 'Boot Device not found' 3F0 error. After doing some research, I was able to determine that changing a setting in the BIOS (switching to legacy support from UEFI) would resolve that and sure enough, the laptop booted up. I thought that was the end of that.

Today once again, I went through the same process - It appears it will always happen now after I disconnect the charger from my laptop. I'm a little worried that this may point towards a deeper issue? Or if it's just to do with the battery.

Additional information: When the battery initially died, it was showing 33% charged but diagnostics were showing errors. However, now it's at 0% and diagnostics don't appear to detect it at all. Alongside this, the time/date in the BIOS is stuck at sometime in 2017. When I do the BIOS change (the legacy support setting needs to be changed every time, it doesn't stick) and the laptop boots up, the time in Windows is the same as when I shut the laptop down, until it synchronises with the internet.

The time discrepancy and the CMOS error made me wonder what exactly the issue could be? A quick look at the forums reveal that this is a problem others have had, but there's no obvious solution given for it. It was mentioned that the CMOS battery might require replacement (I tried a hard reset by holding down the power button, nothing changed) or potentially a motherboard issue.

Another forum post stated that in newer laptops, the CMOS battery may not be there at all, with the main battery acting as the RTC. If the main battery is completely dead and this point is accurate, it would suggest that a battery replacement should fix everything. I just wanted to know whether someone can confirm that's accurate so I can look for international options to obtain the battery.

Many thanks to anyone who can help out.

[Photoray002 · Accepted solution]

Hello @Abdullah719 

I read your post, so I tried investigating the CMOS battery issue for that motherboard. I can tell you HP did not make it easy, as they decided it would be cute to link the next generation of models maintenance manual in place of the correct one 😡.

I finally found the part number for your motherboard and cannot find any data on a CMOS battery. Any photos posted of that board only show the back with a black plastic shroud covering it, so you cant see anything. How brilliant!!!

Because there is no mention of a CMOS battery in the guides, the HP Parts Surfer or content data base, I can only assume there is no CMOS battery.  With what you're describing, it sounds like the main battery is absolutely controlling the bios memory as well. BUT you know what happens when we assume anything. The only sure way to know if a CMOS battery is there, is to physically remove the board and look (it would be on the back of the board, if its there).

If you remove the battery and run the laptop on AC power only (it wont hurt anything if you do), you shouldn't have any problems like having to change the bios to legacy mode every time you boot. But if you do, you either don't have a CMOS battery, or the CMOS battery is there but dead.

I would suggest just disconnecting the main battery and boot in to the bios and reset it (F10).   It should work without having to set the bios to Legacy.

See what happens and please let me know what you find.

Thanks.

[Abdullah719]

Hi @Photoray002

First of all, many thanks for your insightful reply. Appreciate it a lot.

I'll try and do what you've recommended. I was actually intending to do this earlier but one of the screws appears to be somewhat jammed so I was waiting until I could actually take the laptop to a servicing shop, just to have it opened up. Don't want to take any risk because the last time this happened, I didn't know what to do and ended up having to make a hole around the screw and I'd rather not do that with this laptop. Haha.

However, I did try one other thing. Usually I disconnect my AC adapter when I go to sleep, but last night I tried leaving it plugged in. I had a hunch that would ensure that the BIOS settings weren't reset and sure enough, it booted right up normally today without any issues.

I also had a look at the maintenance manual (As you said, it showed the 8750H processor instead of the 7700HQ so not the exact one apparently) and couldn't find any mention of a CMOS battery. I will try and have the battery disconnected today and let you know what happens.

Once again, many thanks for your feedback.