about 2 things comes to mind
as u can see the matrix,which in realty is the post boot rom chk-sum screen
it is either a lose chip >eprom or ram< or your 5volt rail is just undr 4.7 volts..
unplug machine,and push on all the ic's to make sure they are seated right.
then plug machine back in..if it still dose it? there is a control on your power supply
which u can turn up or down to get 5volts back in the range
ed