Bios stuck at 99 error code

[Blisset]

Hi, I've a Asrock 970 Extreme3 R2.0 Motherboard with AMI Uefi Bios P1.60.

Is it "Aptio V" Bios?
In normal boot my PC shows code "A2" (in lower right angle) for about 10-12 seconds, after that it shows code "99" and Sata drives list and boot into windows.

Some times it don't show code "A2", it starts directly with code "99" and remains stuck forever.

I changed FOUR motherboard (all Asrock) but always I've the same issue.

What's the code "99" error?
Is there a list of error codes for my BIOS?
Thank you very much

[Aetherhead]

Aptio V POST codes are available here as a direct pdf download.

A2 is IDE detect, this is your motherboard detecting hard drives and cd/dvd drives.
99 is Super IO initialization, this is when keyboard/mouse and other peripheral devices are being detected.

If this has happened on multiple motherboards then the problem is another device in your computer. Try disconnecting all devices and cables from the motherboard except the 2 power cables, video cable, and the front panel connector (power button, power light, etc). If your computer gets past 99 code then plug in keyboard and mouse and try again. If it gets past 99 again plug in your primary hard drive. Keep doing this, one device at a time until you find the one causing the problem, then replace that device.

[Blisset]

thank you very much