I'm having a problem with the display on my imac 400dv.
the video is jittery and sometimes dark unless i put it to sleep
and wake it back up.
i also have a warped picture that cannot be compensated for in the display properties.
i got this on e-bay(it was like this when i got it)
i wiped the drive and installed os9.0.1.
after updating to 9.2.2,i tried the auto update feature and it reported i was up to date.
i then installed os10.2.8 on my second partition.
the issue was present before i did this.
i quickly found out how much space i needed for os10 and had to repartition the drive and reinstall os9 then os 10.2
i then got a prompt to update my firmware.
i did this and it worked out great.
my video was working fine for a while.
after a few months of very little use,my machine simply turned itself
off one day for no apparent reason.
upon reboot i found that my video issue had returned.
i've searched on the internet for a way to reinstall the firmware.
i haven't found one yet.
i can't help but think that the rom became corrupted.
i have reset pram-vram.
i have replaced the hard drive.
i am at a loss.
any ideas would be appreciated
thanks,
marshall

Having dealt with this with customers coming in let me
explain something. The power, analog and video board
(PAV board) in the G3 iMacs doesn't know how to handle
the video processing of OS X without a firmware update.
Luckily if you have a VGA port at the back of the computer
(usually under a plastic grill-looking cover) you can
connect an external display and see what you are doing
once more. Boot off the drive into OS 9 and redownload
the firmware update from www.apple.com. That should
hopefully fix the issues and you can then run OS X again.

I really don't know why your machine has reverted back to
the previous problem. There have been occasions where
the display itself goes bad and if you have that video port
you can still connect an external display and continue
using the machine.

One last option is to purchase a newer used Mac or get a
brand new Mac Mini. That would upgrade all of your
hardware and software and it wouldn't cost that much.

Good luck!

thanks for the input.
the problem is that the firmware update fixed this issue originally and now the updater says that i am up to date.
i was running a graphic intensive program
when my mac simply turned off.i want to reinstall the firmware but cannot find a way to do this.i suspect that there is a power issue as well and this could be the root cause.i say this because the screen shakes more when the hdd is active.although the distortion is present either way.
i'm thinking i might try reseating all the connections up top but am a bit apprehensive about the crt voltages.i think that if i could fing a utility that would reinstall the firmware update,then it would resolve the issue.possibly flashing the video firmware will help.i cannot afford a new mac or even a tech to fix this one.i've done alot with pc's but this is my first mac.
again,thanks for your input.
thanks,
marshall