I do not know what kind of fans you have got as a replacement for
alpha-based motherboard.  But, you should be very careful about the
pin connection of fan cables.  CPU fans for alpha axps have got
different connection definition for them.  The line colours should
be in the order of black, yellow and red.
If you have got fans for Intel chips, you have to change the cable
positions---from yellow-red-black to black-yellow-red.

If you have got a right fan, then ignore the above.

Yoriaki Fujimori