keyboard becomes unresponsive, stops working

[Simon Andrews]

François Patte wrote:

> I plug an external PS2 keyboard and an external PS2 mouse to a USB port
> of my laptop via a PS2/USB adaptator (CHESEN PS2 to USB Converter) and
> sometimes I have some problems: led of keyboard flashes and during that
> time, I cannot use the keyboard.

A frozen machine and flashing keyboard LEDs could indicate you've had a 
kernel panic.  In this case there may not be anything logged to disk.

Have you tried switching to a virtual terminal (Alt+Control+F2) before 
plugging in your keyboard - you may see a stack trace from the kernel 
panic on screen.