Can't reset BIOS back to original settings

[chroscher]

Hello,

I have a problem, I deactivated all USB ports in BIOS (external, front, internal) too fast without thinking - as I now can't use my USB keyboard. I removed the BIOS battery and start the computer again. The checksum it wrong, so it says I have to type in "502" to reset the BIOS - I still can't use my keyboard to type in the number.

Is there another way to reset the BIOS without first having to use any keyboard?

Many greetings, Christoph

[Prométhée]

Hello
sorry, normally you have two options, the first one you have seems to be tested, only you shouldn't have this problem then
The second, if the motherboard allows it, you would have to move jumpers, unfortunately hp no longer gives the chema for this here!
you should try to contact HP directly, or go to a professional
Try this, turn off the computer and unplug all peripherals
Remove the battery again
unplug the computer from the electrical outlet, press the power button for 30sec
Wait a little longer, and reconnect everything after replacing the battery

[chroscher]

Hello, ok, I also pressed the power button for 30 seconds while battery was removed - still I then have to type in "502" to reset the BIOS. They keyboard Num Lock lamp is on! But I can't type in any numbers. I might have to send the machine in 😞

[Prométhée]

what you have here is an error code
you are not asked to type 502 on the keyboard (unless i m mistake )

https://support.hp.com/us-en/document/ish_4209641-3226345-16

no ?

it could be a problem with corrupted bios, or motherboard

Only what is indicated, often does not work at all with desktop computers

[chroscher]

You are right! I am not supposed to type in "502", sorry, that was my fault.

But still it seems that the CMOS is not resettet, otherwise my keyboard would work.

It says, if I press Enter, the system will be restarted, this does not work. Although my keyboard Num Lock lamp is shining.

[Prométhée]

No no worries, I didn't pay attention the first time
it just seemed strange to me that we asked to type this number
Unfortunately, I can't help you more than that
it looks like you have another problem than the starting one, like i said, bios or damaged motherboard, but i could be wrong
go see a professional if you are no longer under warranty

[chroscher · Accepted solution]

Hej, I finally managed to reset the BIOS to original settings! Removing the battery for some minutes did not work! Although it said, that the checksum was wrong and BIOS would be reset - it did not reset (because my USB ports did not work).

But setting both the jumpers one step to the left, starting the computer, which then loaded for 30 seconds and turned off again, started again, turned off after 30 seconds again ... then I put the jumpers back to original position.

Voila! The BIOS was set to default values and I could use USB keyboard again.

[Prométhée]

I think it might help other users with this same motherboard
can you show this in photo?
well done, although I have procedures for other motherboards, I could not have offered something to you blindly, without being certain

https://support.hp.com/us-en/document/c01700044

[chroscher]

Well, this link, that you posted, shows in principle how it looks like:

https://support.hp.com/us-en/document/c01700044

You have to put both jumpers one step to the left, turn on PC, let it turn off automatically after 30 seconds, then it restarts, and turns off again after 30 seconds (I let this procedure run twice) ...

Then I put the jumpers again to original and started again. Then it said, the BIOS was set to default, and it really was set to default, because I could use the USB ports again.

With the battery option, it only said, that it was set to default, but actually it was not. Although it maybe works aswell when you remove the battery for some hours or so?

[Hobeb]

I did not get witch jumper you are talking about,  can you give little bit more explain please?