>I think this not work. When I got the gray screen, or even blank screen, 
>It seems that the computer not initialized and does not recognize any 
>command. I can't get that screen with the mouse cursor and the floppy 
>blinking looking for the operating system.

Double check you SCSI chain for proper termination. If it isn't right, 
the Mac can get hung trying to find the devices and it may not get as far 
as showing a flashing ? disk. And, try disconnecting the internal hard 
drive as it may be mucking things up (if it is, it will at least get to 
the ? floppy looking for a boot disk)

Also, check your RAM. Try reseating it, and/or swapping it. Bad RAM or 
marginal RAM can also cause it to hang during the memory test. Usually 
bad RAM will cause it to report a sad mac or chimes of doom (depending on 
which mac), but if it is marginal ram, it may just hang during the ram 
test instead.

And of course, going off your battery voltages, you still need a new 
battery, which couldn't hurt to replace anyway.

-chris
<http://www.mythtech.net>