That's interesting. There were no jumpers on the drive, were there? Sometimes drive manufacturers or resellers will ship drives with jumpers installed, as some computers need to have the drive configured as either a 2-device master or slave (or cable select). The 2400's hard drive is on its own bus, so it's a single master (so no jumpers should be installed).
That may be causing your problem, but you'd likely also notice a fairly long delay between the initial grey screen and the happy Mac. It's unlikely to be a power issue, as most Fujitsu drives draw ~500mA, whereas the original IBM drive common in those things pulled between 500 and 1300mA. Some Toshibas, and most Hitachis, will draw well in excess of 1A.
Try booting and sleeping the computer off of a floppy or external drive; if it works, it may be a software issue. If it doesn't work, then it's likely to be hardware. If you dive back in, be sure to check other things, as well; sometimes stuff works even if it's only partially seated.
I'm using a 20GB Fujitsu MHR-series in my 2400c, and have had no problems.
Also, the WallStreet issue occurs because it uses magnetically-engaged sleep, whereas all previous machines use mechanically-engaged sleep. In WallStreets, I recommend only Fujitsu drives to replace the originals, as other brands (not limited to IBM/Hitachi) put the powerful armature magnets directly beneath the magnetic sleep switch on a WallStreet, which often screws with sleep (typically putting it into terminal sleep as soon as the machine finishes booting). This happened to mine when I tried to install a 16GB Toshiba drive, but the problem disappeared when I installed its current 20GB Fujitsu MHN-series drive.
That may be causing your problem, but you'd likely also notice a fairly long delay between the initial grey screen and the happy Mac. It's unlikely to be a power issue, as most Fujitsu drives draw ~500mA, whereas the original IBM drive common in those things pulled between 500 and 1300mA. Some Toshibas, and most Hitachis, will draw well in excess of 1A.
Try booting and sleeping the computer off of a floppy or external drive; if it works, it may be a software issue. If it doesn't work, then it's likely to be hardware. If you dive back in, be sure to check other things, as well; sometimes stuff works even if it's only partially seated.
I'm using a 20GB Fujitsu MHR-series in my 2400c, and have had no problems.
Also, the WallStreet issue occurs because it uses magnetically-engaged sleep, whereas all previous machines use mechanically-engaged sleep. In WallStreets, I recommend only Fujitsu drives to replace the originals, as other brands (not limited to IBM/Hitachi) put the powerful armature magnets directly beneath the magnetic sleep switch on a WallStreet, which often screws with sleep (typically putting it into terminal sleep as soon as the machine finishes booting). This happened to mine when I tried to install a 16GB Toshiba drive, but the problem disappeared when I installed its current 20GB Fujitsu MHN-series drive.