After doing everything, i found my solution. The cmos battery wire is the problem. Glad i tried changing the wire. I was about to solder new bios chip!

I clicked enter and it fixed it!

HI, I did as advised but the message is ( The selected boot device failed) what can I do more?

Hi, i have the same problem. Except that mine started when i replaced my old battery with a new one. It was working fine for a few weeks before i got this problem.

If I do not solve the problem and it persists, will it affect the device over time? I use it now normally despite the problem

Hi, I recently changed my battery as the old one was not holding up the power and turned off by itself many times. after i changed, this cmos problem screen has been keep on showing up every time i turn on my laptop. How do i fix this? The battery is new.

I remove the battery and using the power plug directly , i get the error message everytime i turn on the laptop . CMOS reset ( pressing enter) able to log in my laptop . May i know any impact if i continue in this way.

So, if I am just happy with plugging in the laptop and don't care about battery replacement, will it be bad in the long run? ... I mean I keep having this CMOS message but I continue to boot to windows normally. I am in this state for 2 months and nothing bad happened till now and I hope it stays that way :)

Thanks, it is useful to solve my HP laptop.

We replaced our battery from normal wear and tear and it was working great, even unplugged, but my daughter ran Minecraft on it until the battery was at 3% basically. Now its showing this error and not charging. Do you think we got too cheap of a replacement battery? It is 3rd party I'm pretty sure. (Hubby bought it)

I changed battery after showing 502 eror but still error showing and shut down laptop and turn on after 30 minute laptop not turn on without plug in charger but when i plugged in laptop start with 502 error. Plz.. Help me...

I replaced the battery last years and now this error, I'm pissed off

Thanks for sharing information

its coming after i replaced my battery its coming in new battery what to do?

If you connect the battery terminal backwards, is there a possibility that the bios no longer works?

Sir when i plug in then laptop working fine without changing bettery.

I have an hp stream x360. I unplugged the battery internally and just had the power supply plugged in. it started right up after hitting "enter" on the error screen. Guess I'll be changing out the battery next.

so the thing is we have a lot laptop here same type of issue is happening but battery can hold the charge well backup is around 2-3 hours, but still sometimes bios resets and it gives the cmos checksum error (during testing we found after we set everything and the 2 day later the bios got reset again and gave cmos checksum error) what are the options is it a faulty battery?

Thank you very much

I had the same problem and ordered an original battery to replace the old one, however after a few hours of use the blue screen of death started to appaer and my laptop wouldn't stop restarting because the BSD appeared every time. I ran the diagnostics tool and the battery seemed to be good. Then I removed the battery and the BSD still appeared so I just restored windows to a previous state and the BSD was gone, Then I reinstalled the battery and the BSD was back and the worse part is that it completely damaged my SSD NVME. So now I ordered another NVME but I'm not sure if should reintall the battery since I don't want it to damage the ssd again. Any advices?

He’s comparing the external battery to windows error?? No… not at all. The error is provided when there’s a problem with the CMOS battery on the motherboard. Just change the battery and load your bios to defaults, then reinstall the newest bios firmware

Thank You Very Much

Hi, Is the problem related to the main battery or the CMOS battery?

I was, Replace to new Battery but still same error, (battery time ussage still normal) (My Device don't have CMOS Battery)

Hi thanks my but my laptop is already working when ı dont charce it and sometimes its giving cmod error and closing sometimes too so my battery died? And ı see the Amazon link is it this laptops original battery

I replaced the battery it didnt work....

Whereis CMOs battery? Location pls

My battery is almost new I took it out and put it back in and hit enter but it brought me to boot device not found screen

I replace the battery and i still have the error message

great. thanks

I changed battery and now I just have a blank screen.

I use this same laptop my battery stop working few days ago so it now become plug and play and I have been having such cmos messages I think I need to get the battery replace

I changed the battery but i still get the error.

My dead battery was replaced and from that point, this error keeps occuring. I cannot power on my laptop unless I plug it for a moment then press the power button. After that, I can use it unplugged. What seems to be the problem?