40/80 key isnt pressed

with my action replay plugged in it boots to the blue 64 screen with nothing on it
with my freeze frame plugged in it boots to a black screen

i have checked the psu and it's pushing out the right amount of power
i can also hear the 1571 drive click when i turn it on so it's initializing the floppy drive

hi all,am after a bit of help
my c128D has become poorly
on startup all i get is a black screen but if i hold down the commodore key while i start it up i get the light blue c64 background screen with the border but thats it, no text is shown at all
anyone got a idea as to wot the cause could be?

cheers