GA-Z68a-D3H-B3 hang on boot, tab not show POST

[hikerlt]

Seeking advice.
For some time now, during boot of my GA-Z68a-D3H-B3 with CPU Intellicore I5 2500k 3.3G 6M R processor

when I press the tab key, doesn't seem to want to show the POST activity.

This morning, the PC hung - stopped at what I assume is beginning POST, display screen showing the Gigabyte logo start screen. Pressing the tab, or delete, or F12 - nothing seemed to work. Power cycled multiple times, still hung frozen at boot up.
I wasn't until I plugged in a 2nd USB keyboard, and was hitting the TAB key and Delete Keys multiple times, that the PC seemed to get past that frozen/hung point, displayed the POST results, and then booted.

Any idea what is happening here ?
What should i expect to see on boot up and hitting the TAB key - should it be showing POST activity, such as memory test, etc. - or just show the results after POST is done ?

Thanks in advance for any help and advice on this 11 year old PC.

[dmdilks]

One thing you can try is plugging in the Ps2 keyboard. Or check to see how the USB ports are set in the Bios.

I use a KVM Switch to work on computers that way I can have up to 4 computer connected. But some times the older boards just don't like the KVM Switch or USB keyboards.