so if the iBook turns on normal with desktop on the screen with the old harddrive ,
and the screen stays dark with the new harddrive and if the jumper settings are as they are supposed to be
then i take a guess and say the new harddrive came DOA or it was never meant for the iBook , but i am not sure about that because its a long long time ago i came across a 20gb p-ata 2.5"
i googeled a bit and came across that little bit in wiki , but that is now a extremely wild guess with that
Integrated Drive Electronics (IDE), later renamed to ATA, with the alias P-ATA ("parallel ATA") retroactively added upon introduction of the new variant Serial ATA. The original name reflected the innovative integration of HDD controller with HDD itself, which was not found in earlier disks. Moving the HDD controller from the interface card to the disk drive helped to standardize interfaces, and to reduce the cost and complexity. The 40 pin IDE/ATA connection transfers 16 bits of data at a time on the data cable. The data cable was originally 40 conductor, but later higher speed requirements for data transfer to and from the hard drive led to an "ultra DMA" mode, known as UDMA.
Progressively faster versions of this standard ultimately added the requirement for an 80 conductor variant of the same cable; where half of the conductors provides grounding necessary for enhanced high-speed signal quality by reducing cross talk. The interface for 80 conductor only has 39 pins, the missing pin acting as a key to prevent incorrect insertion of the connector to an incompatible socket, a common cause of disk and controller damage.
that is really only a wild wild wild guess that it is one of the earlier harddrives or a doa , but would explain why your ibook is not booting with it as the open firmware looks first for the harddrive and then for the screen if i am informed right so it does not get to the screen and stops booting at that point
i am totally
now and could be totally on the wrong path and there is a simple solution to the problem and i just cant see the forest because of all the trees