No longer able to get into BIOS

System is a new (4 month old) B450-HDV R.4.0, AMD Ryzen 3. 8 GB RAM. OS is Windows 10 Pro 64 bit Build 18363. Two 500 GB SSDs Been having some issues with I/O (RS-232) and a few other things but basically the Win 10 system is stable and working with a few issues I've been living with and currently troubleshooting.

Recently I opened the BIOS and disabled the mobo RS-232 serial port to test something. Did my testing etc. and then a few days later tried to get back into the BIOS to re-enable the Serial port. But now I can NOT get into the BIOS any more.
I've read just about everything relevant thread on this forum and others and tried all the fixes for this "BIOS access problem".
Note .. this is a dual boot system that works okay. Upon turn on I get the normal post screen .. offering to use F11 for boot menu, F2 or Del for boot to BIOS. If I do nothing it then automatically brings up a boot menu where I can use my keyboard to select either windows 10 or windows 7. That all works fine. However IF during the initial post screen showing F11 / F2/ Del, I touch any key .. the screen goes black. Can't use any of those options. But if I wait for my "auto-loading" second dual boot option screen to appear .. the keyboard is responsive and I can select an OS to boot.

I've been using it to boot to BIOS with my wireless Keyboard and Mouse normally and used to be able to hit <del> or F2 or F11 but now hitting any of those keys creates a dead computer .. no screen or control and I have to do a hard reset.
I have the ASRock software application "Restart to UFI Bios option" installed and that used to work, but doesn't now. Between the time it was working and then not working there were a few major windows OS updates. Don't know if that might have caused a problem ?

I've tried the Win Settings / Recovery to Advanced options (UEFI Firmware Settings) but that option isn't even listed ??
The actual BIOS is still the original as installed a few months ago .. (1.0) I was told by Asrock to NOT do a BIOS upgrade with my current mobo/CPU. So I haven't touched that.

BTW, I've also installed a wired USB KB, as well as a wired PS2 keyboard. The Mobo has a PS-2 port and right next to that port are two dedicated USB-2 ports which are normally for a kb and mouse. Nothing works. They all "used to work".
Most weird is how during the post while it's waiting for me to hit Del F2 or F11 it will just sit there until it automatically runs my dual boot option at which time the keyboard does work. But If I touch ANY KEY during that initial wait for my input .. the screen goes black and the PC is unresponsive.

So my question (if you've stuck with me so far <grin>) is this. I haven't done a BIOS update in years. My next try would be to do a hard reset of the BIOS .. pulling the plug and draining the CMOS and letting it reset back to factory settings. I will image the hard drives of course but I'm curious if re-setting the BIOS will have any adverse effects on my programs or OS ??
Of course I'm hoping I missed something and someone here might have a suggestion. This PC is not the one used in my forum Profile .. system Info is at top of post. Thanks

I would power off the system.

Then, hold down the F2 key...don't release it.

Power on the system.

Wow .. that was a fast reply !! Nope .. holding down the F2 and powering up results in it booting directly into Windows 10. (think in my dual boot thing it's set to default to the win 10 system) .. But it looks like the F2 key is being bypassed and it's not even loading my working dual boot menu and instead going right to 10 OS.

OldNavyGuy said:

I would power off the system.

Then, hold down the F2 key...don't release it.

Power on the system.

Could also be the keyboard.

All else fails, try another.

Well I just got back from dinner .. and found a bunch of replies. This is certainly a responsive forum ! <grin> Thanks.

For Ghot: thanks .. Pretty familiar with PC systems .. I'm leaning toward doing the bios re-set but will try some others first. BTW my first computer was a home built kit SWTP (early 70s I think) .. That was slow ... I also have a modern home built .. water cooled over-clocked PC I use for video editing . Darn thing boots FAST ... And I'm an old 74 year old codger whose fingers often don't move fast enough to hit F2 ... <grin>

For OldNavyGuy I did mention I tried both wired and wireless and PS-2 keyboards. I have at least a dozen types laying around here. They are all good .. and aren't the issue.

For Ghot I have the ASRock App shop as well as the mobo "A-Tuning" and "ASRock Restart UEFI" apps installed. Used the A-Tuning and the Restart UEFI (which have an option to disable on start). In both cases the Windows Startup is NOT enabled. However I'll take a look at the "Asrock App Shop" thing .. Don't remember if that is on or off . I'll check and get back.

I really appreciate the help ... Rich

Do you have fast start turned on in the power settings? Try turning off the computer and unplugging the power cord. With the cord unplugged hit hold the power button for a few seconds. This will drain any remaining power in the computer. Plug the computer back in and hit the power button then what ever key your computer uses to access the Bios.

Try removing one of your memory sticks, or your hard drive.

It may force the prompt because of the hardware change.

Hi Winuser: Good idea about the "fast boot" .. FWIW in my power options in this mobo, there is an option for " AMD Ryzen Balanced". I never bothered to look further when setting it up. But I just changed the power option from that AMD thing and found buried a few more settings one of which was "Fast Start". However that "sub menu" had everything "greyed out" AND they were all enabled. I had to dig out the manual to figure out that when I selected the "AMD Ryzen Balanced" power option, it auto set a bunch of power and performance options that were sorta hidden in a sub menu. In order to turn OFF the Fast Start option I had to Disable the "AMD Ryzen Balanced" power main setting. Now I have all those formerly un-changable power options (like Fast Start) able to be configured. Well hang on . while I slide over to the other computer and give see if that made a difference.

Old Navy Guy Hang while I try the newly found "fast start" option change. BTW, one of the reasons this whole thing started was because I've been troubleshooting a few nagging problems. ONE of which is this mobo will not work with more than one memory stick installed. (I can ONLY get it to work with one 8 GB stick. Originally I had a matched set of GSkill 8 GB and had all kinds of issues with memory. both sticks are good. A month ago when I started working on this (I had Serial port problems and memory problems) and this inability to now boot into the BIOS is yet another "new" one. My first gut reaction when I built this thing was "I got a mobo problem". Sigh .. Thanks to you guys .. I might be zeroing in on a problem common to everything ? More later ..

- - - Updated - - -

Update: No change .. with or without "Fast Start" enabled. Up next will be the CMOS clear and re-set. That's gonna be tomorrow morning. Will report back. Meanwhile still entertaining any other options.