Mac Forum / General / Portable Macs / July 2006

hello there,

my ibook (g4, 1.3ghz) is not resetting the pram anymore when pressing
command-option-p-r at start-up and i have no idea why. i tried it a
thousand times at different times (before, while, after the chimes).
resetting the nvram via open firmware prompt did work. however, i did
not get to the open firmware prompt by command-option-o-f, but after
resetting the pmu a few times via shift-option-power. now the system
boots into the firmware prompt every time. it shows an "invalid memory
access at .." message at the top. when i managed to get to the firmware
prompt before it showed diffent messages like "floating point
unavailable" and "illegal instruction".

the reason why i am trying to reset the pram is that the system was
stopping with a black screen when starting up. i did manage to reset
the pram once in the beginning, my system was booting up at froze with
a white screen "you have to switch off.." and from then on i got the
funny behaviour described above. booting with "C" or option key also
does not work.

any ideas? hardware fault?

thanks, meinhard.