You need to get yourself to the Apple download site and download a startup floppy image (anything system 7 should be fine). This should allow you to get into your Quadra and check what state it's in.

If the worst comes to worst and you can't find any install media or can't repair the machine, the Apple site linked to above has several complete sets of Mac OS install disks to download and use.

All of this assumes of course that you can get past the 'sad Mac' stage. Try pulling all of the RAM and boot with no SIMMs installed at all - if this works then your memory could be damaged and you'll have to try working through the modules until you find the stick that's gone AWOL