Trying to revive a server... AIC-7896 freezes pre-POST completion

Andrew Reitz ajr9 at
Wed Jun 14 07:55:56 UTC 2006

On Jun 13, 2006, at 10:11 PM, Garrett Cooper wrote:

> Hello again all,
> 	I know this isn't a FreeBSD question really, but I just started up  
> a motherboard with onboard SCSI (Adaptec AIC-7896), and for some  
> odd reason it freezes pre-POST before it attempts to boot and there  
> isn't any way where I can get into the BIOS to change the settings  
> it seems. Does anyone know how I can maybe disable the onboard SCSI  
> controller since it appears to hang while detecting disks?

Hi Garrett,

I've been having a lot of "PC fails to POST" problems recently, so I  
feel your pain.

Basically, my guess is that after your BIOS does its self check, it  
tries to load all of the option BIOSes into memory. This will include  
a BIOS from your SCSI adapter, as well as network-bootable NICs, etc.  
Basically, the BIOS has to do this so that you can boot off whatever  
option card that you have in the system.

Since your SCSI adapter is built-in to the motherboard, it should be  
pretty compatible with the BIOS -- unless you changed that recently.  
In order to troubleshoot this, however, I would start by unplugging  
everything possible from your server. Just keep the ram, MB, CPU, and  
graphics card. See if you can get the machine to POST in this state  
(it really should, barring some sort of bad hardware or bad CMOS  
state). If it posts, start adding things back (disks, PCI cards,  
etc.), until you find the source of the problem.

Usually, onboard devices can only be disabled from the BIOS, which  
you can't get to. But, I would check for a jumper on the motherboard,  
to see if there is a way to disable things that way.

If you get really desperate, you could try resetting your BIOS  
configuration (CMOS).

Good luck, and I hope this helps...

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