IIGS ROM 03 Startup error

[Brendan Bellina <bbellina@iusb.edu>]

I recently purchased a ROM 03 IIGS and attached it to my home network
along with my ROM 01 GS and Macintosh.  Although it has no hard drive, I
was able to get enough of System 6.0.1 on floppy to attach to the Mac
and load the Finder off of it.  Things were looking good for a week or
so and then the machine refused to boot up. I've owned Apple II's since
1980 and a ROM 01 GS since 1986, so I know enough to have tried several
things including swapping out the power supply, removing all peripheral
cards, including the memory card, using a different floppy drive, even
booting without a drive at all, but I get the same results regardless of
anything I try.  Basically when starting it up the screen remains
completely black, no text at all and no startup beep.  I can start the
self-test and it appears and runs fine, reporting that the system is
good, but I can't get to anything else.  Pressing OA-Reset causes the
screen border to blink white twice, pause, and blink again, then nothing
else happens. I cannot get to the Control Panel.

I've also opened it up and visually scanned the motherboard for
darkened, loose, or corroded chips, but everything looks fine.

I'm afraid that whatever chip controls the startup ROM code has gone bad
and the motherboard will be replaced, but I'm hoping that someone may
have a suggestion.  Any help is appreciated.

Thanks,
Brendan Bellina