iMac 350 firmware fix:

So you tried to install os X 10.2 without updating your firmware to 4.1.9 and now you don’t have any video…. 
Well here’s what I did to fix my iMac.

First I removed the hard drive from the iMac and plugged it into my G3 B&W tower.

I loaded a clean install of OS 9.1, set a static IP address, then downloaded VNC and the updated firmware (4.1.9)

I installed VNC Server and copied it to the startup folder so it would start everytime I booted the iMac.

I put the hard drive back in the iMac and booted it up.  

I VNC’d into the iMac with my powerbook and ran the firmware update.

I shutdown the iMac and turned it back on with the programmers button held.  Released when the long tone sounds.  
The iMac did the firmware update and made the startup sound a couple times.  I then powered off the iMac and Zapped
the PRAM (hold command option P R and let it bong for 3 cycles).  Let go of the keys after the third cycle and 
WOO HOO I got video again and the computer boots and tells me that the firmware update was successful.