View Full Version : iMac G3 Wont Turn On!

8th March 2005, 05:25 PM
hey guys,
im new to the apple world
i have recently come into possesion of a few G3 imacs
(400MHz, 256Mb RAM)
i plugged them in and found that 2 sound like they start up but the monitor doesnt turn on, and the other 1 doesnt turn on at all! :huh:
i opened them up and found that the HDD's were missing, so i connected a working apple HDD from another functional imac (same specs)
but the same thing happened again! :angry:

so if anyone has any ideas or can give me some insight please reply

kind regards

8th March 2005, 05:33 PM
The iMac G3's are subject to analogue board failure. I have had quite a few Bondi blue iMacs fail this way. It could be why the HD's had been removed - spare part scavenging. The computer starts but then detects that the analogue board has failed - no screen will come on and the computer may shutdown.



8th March 2005, 05:44 PM
Thanks for the info Paul
is there anyway to fix this board, or maybe even buy a new/second hand 1

and if so is it worth it?

Kind regards

8th March 2005, 05:55 PM
The QLD police moved over from Macs to PC's a few years ago and flooded the market with G3 iMacs (among other models) and this made them not worth repairing as replacement cost was only a few hundred dollars. I don't repair mine at my school, as I was given 31 of them a while back, I just strip them for parts but you could try getting spare parts from some place like Powertech in Brisbane.


8th March 2005, 05:59 PM
thanks yet again paul

i think ill do what u did and strip them, at least i get a gig of new RAM :D

thanks for the help


8th March 2005, 06:00 PM
With what we have already discussed, the logic board failure seems most likely. Maybe you try the logic board from one of your guaranteed working machines into the failed ones, and trying to see of that works. The possibility is, if this makes the computer work, you may be able to look on eBay (I know how much you hate doing that) and looking for another G3 iMac to gopher parts from. Somebody else here may be able to help more, remember I just use Macs, not fix them.

Good luck Matt.

8th March 2005, 06:09 PM
Hey paxton whats up

paul said that its the analogue board and you say the logic board

which is it?

8th March 2005, 06:16 PM
Originally posted by Aussie@Mar 8 2005, 06:09 PM
Hey paxton whats up

paul said that its the analogue board and you say the logic board

which is it?
Ok, let me clarify, it is the analog board.

Based on information we gathered, the analog and video boards in the Rev. A-E iMac's are the main source of failure, and it's generally the analog board (the circuitry that provides power to the CRT) which goes. According to one technician, it's usually the flyback transformer that fails

Taken From Low End Mac.

Hope This Helps.

kim jong il
8th March 2005, 06:53 PM
One of my imacs was bought (very) cheap a few years ago because a tech had determined that the analogue board had failed. After many hours of research I updated the firmware (has to be done under OS 9) and the monitor blinked into life. It was perfect. Prior to 10.2 installing OS X could and often did send the analogue board into spasms making it appear, for all intents and purposes, that the analogue board, or more specifically the flyback transformer, was dead or dying.

Assuming all parts are in place and the thing chimes on startup and is the model that has a VGA port (G3 400s and above) I would advise plugging in an external monitor and check the firmware revision. If it is not 4.1.9f update it and you could be in for a nice surprise.


EDIT: I have deliberately spelled analogue as analogue. This is Australia and we, notionally, speak the queens English not the presidents. If you are searching for information you will need to use the american word analog

8th March 2005, 08:51 PM
Thanks for the glimpse of hope kim
but when the G3's start up, there isnt a chime !

and thankyou kim for spelling analogue correctly, i hate it when everyone spells american

anyway thanks again


9th March 2005, 12:50 PM
So is there any hope of repairing them if there isnt a chime??

could it be that the volume is turned down or that the speakers are stuffed altogether?


11th March 2005, 06:12 PM
Wow i'm kida excited after reading your post kim! i got a imac 400dv and was starting up well untill i tried to install OSX and lost the monitor!!! I get a good connection out of the vga out to my sony crt! Managed to get a crappy picture out of shape and wrong colour on imac, but unbearable to view. I am running 8.6, do I need to to have os 9 for the firmware update?

Many thanks :unsure:

11th March 2005, 07:08 PM
yep the problem is prolly coz after osX is installed on a iMac without the firmware being updated then the screen goes dead, and the mac will turn on... what you need to do.. is boot off a OS9 disc or sumthing... and some how download and install the firmware...

12th March 2005, 10:11 AM
where is the firmware info located in the imac?


12th March 2005, 10:14 AM
In the ROM chips on the motherboard.

12th March 2005, 10:43 AM
sorry, new to all this! can i check it in system profiler or physically look on the motherboard?


12th March 2005, 11:00 AM
You have to check in Apple System Profiler.

12th March 2005, 11:06 AM
thanks :rolleyes: