iMac g4 monitor dark

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Joined: Jun 1 2013
Posts: 2

I have a iMac G4 1.25mhz. I just swapped out the power supply and battery. Now the computer works (boot chime ok, fan, ok.), but the screen is too dark. There are a lot of different arguments on the forums, most of which are to just connect an external monitor. Other arguments include the backlight being out, and the inverter board being out. I don't even know what an inverter board is. HELP!

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Joined: Dec 11 2011
Posts: 66
Re: iMac g4 monitor dark

Make sure you have the brightness all the way up, sometimes I've seen imacs reset and have the brightness set to 0

If it's almost completely dark (turn off the lights and you cannot see anything from the screen), it might be the inverter, if still lights up, then I don't think it would be the inverter, maybe a wire or connector on the cable was damaged. I have never replaced an inverter in these, but I'm almost positive it's in with the screen, not in the base. There should be screws on the bottom of the screen, remove those and the bezel should slide up and off, the inverter is usually a long board next to the LCD, if not, it's probably behind the screen, see if you can find the (usually 2, maybe 4 if it's the 20" one) pairs of wires from the screen and follow them to the inverter.

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Joined: Jun 1 2013
Posts: 2
Re: iMac g4 monitor dark

Some people have said that in the re-assembly process ( I just swapped out the power supply), the video cable could get pinches,or otherwise damaged. If that was the case, there would be no display, right? My problem is that the display works, but just doesn't light up. I guess I will be buying a new inverter. Hopefully that fixes the problem. I will keep you informed.

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Joined: Dec 11 2011
Posts: 66
Re: iMac g4 monitor dark

Probably, I haven't looked at these in a long time. The one I have here (15") isn't opened, so I can't see the inverter easliy, but it has a cable labeled 'inverter cable' which I assume is the power to the inverter. if that's not plugged in, or was damaged that could certainly be the cause.