Thanks for your response, equill--

No, the floppy drive is completely empty. I think it may need replacing...

And after a bit of research, I understand more about all this, and I simply realized that Option had no effect because I removed the internal HD (which is non-working anyway) and the FDD is stuck!

Since there's no startup device at all, it had no choice but to go back to the error screen.

So I'll get a replacement hard drive and floppy drive, install them, have a look at the chips on the logic board, and if a blast of air doesn't help, I'll simply replace the logic board.

And, of course, I'll keep the broken version of each component I replace so that I can still work on them and, hopefully, fix them.

BTW, I think the 3 may also mean that the SE performed an 'illegal instruction'. That's what many error-decoding websites told me, in addition to the fact that the SE had flashed up a dialog box beforehand informing me of an illegal instruction.

So I'll do all of what I listed above, and I'll just hope that a good HDD and a permanent OS installation will help. And, of course, I'll try and track down the chip that the error code identifies.

Thanks equill,

-Apostrophe