View Full Version : Help- No Display

22nd June 2005, 08:22 AM
here's one for sod's law --- Just sold my imac on ebay - so pulled it out to give it a fresh install, set it up, booted from dvd it did the install then warned me of errors, rebooted and no display.

reset the pram using the keyboard - nothing
pulled out the pram battery for 10 mins - nothing
put the drive in my external case and installed - nothing

Please help

22nd June 2005, 08:27 AM
which imac is it?

also, is it completely dead, or just no display with everything else seems to sound working?

had the same experience on my old imac233,
perhaps it need a new battery?

the battery in my imac 233 was so bad that if i had it unplugged from the wall more than several minutes, i need to open up everything and reset the cuda switch.

22nd June 2005, 08:29 AM
ooops sorry it's an imac dv se 400mhz with 192mb 30gb - slot load dvd

22nd June 2005, 10:26 AM
if you perviously had 9.x on there and are now install 10.2 or above then it needs a firware upgrade otherwise this exact problem occurs. if your not then don't worry about this message.

22nd June 2005, 05:16 PM
All the drives spinup, power light comes on and stays on, startup chime is heard.

just had new pram battery couple of weeks ago.

firmware has been updated previously

can plug an external display in no problem, just the built in display has no picture.

should have put all this in my original post.

had just got a really good price for it on ebay too!!!!

that was gonna go towards my g5 fund


22nd June 2005, 05:45 PM
the imac send the image out the vga port out the back straight from the logic board. the crt internal monitor gets its power and picture from the video/power board (the one you see by looking it out the top). therefore if you can see on an external you logic is fine and therefore your issue is in the video board. it is a good idea to get it reseated as you will find that parts can come loose, if that fails then you need a new board which is a couple of hundred dollars, and hence, not worth it.


23rd June 2005, 03:44 AM
I think then that i'll pull it to pieces at the weekend and do just that, if that does not work then it's gonna be a parts sale on ebay.

thanks for all the suggestions.

Mac Aid
23rd June 2005, 09:44 PM
What you describe sounds exactly like the firmware issue. I know you said you updated it previously, but I would download the latest and try that first before taking to it with a screw driver.

If the firmware update doesn't fix it, it's likely the PAV (Power-Ananlog-Video) Board, and you won't be able to fix it by playing. Also, be very carefull of working around the CRT, as the 22-25KV can kill you if you don't discharge it properly.

There is a usefull article on the firmware issue here: http://www.capecodgraphics.com/imac_firmware.htm

Good Luck!

23rd June 2005, 10:30 PM
thats exactly what i first said, and while you can't usually fix the Power analog vid board a by playing with it i have seen a few come thought mmy service centre that simply needed the board properly attached at the neck and the screw re tightened. its a long shot but worth doing before pronouncing it dead.

if he does in fact have the 4.1.9 (i think it is) firmware installed then its hardware.

anyway, i again put my weight behing the firmware things as the culprit, then next likely the board is dead, but if the firmware doesn't fix it then its worth opening the baby up. i would not recommend it unless you know how to discharge the CRT.