I have a PowerBook 180 running Mac OS 7.5.5 with an intermittant booting problem. About 98% of the time when I start the machine up, all I get is the "missing disk" error symbol (question mark on a disk icon), as if it can't find the internal hard drive. I don't think it's a physical problem with the hard drive because of this: when I boot the machine with a bootable floppy disk (the one I usually use happens to be a OS 7.6 Disk Tools disk), it can see the hard drive fine and all the files on it. And here's the key -- when I soft restart from within the disk-booted OS 7.6, it ejects the disk, then proceeds to happily boot from OS 7.5.5 that is installed on the internal hard drive. Everything works fine until I power the machine down all the way, and upon attemping to boot again after that, I will get the "missing disk" error again.
This behavior makes me think that there is something wrong with the record on the HD that tells the Mac that it's bootable, however that works. I have a lot more experience in the DOS/Windows world and the best analogy I can think of is a corrupted Master Boot Record (MBR). I am not too familiar with the mechanics of classic Mac OS or its file system, so I'm not at all sure how to fix it. I am wondering if there is a way to restore this "boot record" on the internal hard drive without completely reinstalling the OS. Also, any explanation as to how Macintosh hard disk boot records work would be helpful.
Any ideas? Thanks a ton in advance!