2018-07-06

Recently I modified /etc/default/grub to change the GRUB_DEFAULT value from 0 to 2 in order to run Memtest86+ on my Linux Mint 13.8 computer. I realized only afterwards that this was a very bad thing for me to do. Ever since then, Linux Mint 18.3 just runs this memory test on and on whenever I boot up the system. Hitting the ESC or any other keys fails to achieve anything. In short the program just ignores all keyboard inputs. I don't think the problem has anything to do with BIOS.

Could this be a Linux problem? I've never experienced this sort of problem while running Ubuntu. Any help will be much appreciated.

Julianvb

Memtest86+ is a standalone program that runs independent of the operating system - it needs to for full access to RAM. It can't access memory in use by the operating system or software running on it to be able to test memory.

If hitting ESC while running Memtest86+ doesn't close it and restart the machine, it's either a problem with Memtest86+ or far more likely a hardware issue.

Does your keyboard respond in Linux Mint?

Fix grub or catch it at boot and edit or boot to live media to fix grub.

Hi, jsbjsb001 and jefro,

Linux Mint responds to the keyboard OK. My LM boot menu does not respond to the keyboard either. In other words when the grub boot menu appears, it's inaccessible (frozen). I've attemted to use a live LM USB to fix the problem in vain. Even the new installation's boot menu is identically frozen even though all the boot choices are displayed but they are 'untouchable'. In other words, the menu is frozen solid. I don't know how else to describe my problem. I really hate to lose all my existing files on account of this sick Memtest86+.

Since Memetst86+ has captured the whole system, obviously I have no hope of fixing the problem.

I tend to suspect this to be a Linux problem because my other computer that hosts Windows XP and Linux Mint 13.8 also denies me access to LM18.3 because the (frozen) boot menu would not respond to the keyboard. Here I've two separate machines manifesting the same malady.

Thanks you very much.

Julianvb

Check your BIOS settings for things like "Legacy USB Support". You will probably find it disabled, which leaves the keyboard enabled during BIOS/EFI setup and enabled again once the OS loads a driver, but disabled during the boot sequence or in programs like memtest86+ which do not have a specific driver for the USB hardware.

I've looked high and low for the past several wees or so for 'Legacy USB Support' in my Phoenix AwardBIOS version 6 in vain.

Thanks very much for your valuable input.

Julianvb

It might be a BIOS problem. How old are your computers and do they have a PS/2 keyboard port?

If USB legacy support is not enabled in the BIOS (assuming the option exists) then the computer will only respond to PS/2 keyboard inputs until the USB keyboard drivers are loaded. Which is why neither grub or Memtestx86+ work.

To late...

Some computers may not use all of the usb ports or the usb port chipset isn't supported in memtest? USB hub may be goofy too.

Hi,michaelk,

I can't thank you enough for awakening me. All my 2012 Jetway mini-motherboard machines do come with a PS/2 port (for keyboards). At one point I somehow forgot to keep this important point in mind since most of my keyboards are the USB type and they are easier to connect. Luckily I still have a PS/2 keyboard left over from my old Gateway Windows 98 computer. I should have been more attentive. I should not have suspected Linux to be my problem source and am glad that you corrected my erroneous assumption.

I hereby post the following reminder for myself and others who might stumble into this trap inadvertently in the future. I can't tell you how much I owe both you and LinuxQuestions.org.


Julianvb