Issues with Athlon 2400+ on A7V8X-X

Hello all,

This is my first message on this ML. Previously I was only subscribed on 
the FreeBSD-PPC, so I'm not sure if there is any protocol to this ML 
that I'm skipping. Apologies in advance.


Hardware:

CPU: AMD Athlon 2400+

M.board: A7V8X-X, bios 1014 beta 2 (I also tried with 1008)

RAM: 2GB

HDD: PATA 40GB


FreeBSD 13.1 refuses to move from initial bootloader menu. It loads the 
kernel and modules and after that freezes completely (Ctrl + Alt + Del 
doesn't work, powerbutton doesn't work).

Linux boots and works perfectly, RAM has been memchecked whole night, 
I've removed all the PCI cards and even the AGP card and same results 
appears to occur.


I tried booting from CD-ROM, and also I installed FBSD from another 
computer (here it boots absolutely fine) and then attaching the HDD; 
None of this approaches seems to work on this particular system.


On a different note (it might be relevant) the USB keyboard seems to 
become extremely unresponsive when moving around the bootloader (I need 
to start pressing buttons until it starts responding, pretty odd indeed).



I'll start going backwards trying previous versions of FreeBSD to see if 
I can make it boot at all. In the meantime I'd like to know:

- What is the best way to diagnose this kind of issue?, is there any 
verbose mode I can enable on the bootloader?

- In case I need to start debugging, is there any approach to this? 
(beyond attaching a JTAG to the board).


Thank you very much in advance,

Javier Bizcocho.