iMac G4 20" USB 2.0 iLamp Help from Seniors

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Last seen: 10 years 2 months ago
Joined: Apr 12 2008 - 02:49
iMac G4 20" USB 2.0 iLamp Help from Seniors

Dear All,

I've got the pleasure of receiving that great piece of hardware a iMac G4 20". But it came with a few problems:

Someone had stripped and tried to fix the poor thing, the problem begun with stripped torx screws and missing vital parts inside.

As half of the power supply was missing I've got another one on E-bay from a iMac G4 17" .

To be short:

At this moment I've got it to turn on and I can hear the chime, Fan, Hard Drive and CD-ROM all working.
I could even boot with Gentoo PPC Install CD (linux) but I cannot see anything without turning all the lights off.
Yes the thing boots the CD and asks me for boot parameters. But the problems is that the screen is really really really faint. To the point that I can only read when I turn all the lights off at night-time.

I heard that the monitor has 2 fluorescent bulbs so I believe the problem is with the inverter or the inverter cables.
I'm trying to keep the repair as inexpensive as possible as the machine came with missing bottom, missing hard drive, only half of the power supply and now the screen is faint, only 256MB of RAM, no Mac OS X discs, no keyboard, no mouse and I need to be cautious about logic errors that could appear after having the OS on it.

Question 1:
I've replaced the power supply from a iMac G4 17" Power Supply, Part Number: 614-0206
The 16-PIN connector is the same. The only difference is that PIN-9 is Yellow and on the old power supply that was there before PIN-9 was Green.
Should it be causing a problem with the LCD Inverter ?

Question 2:
Is it true that if the screen is really faint and I can only see in pitch black dark room the problem is the inverter or it still could be the fluorescent bulb or other LCD part?

Question 3:
Have anyone replaced a power supply from a iMac G4 20" from a iMac G4 17" without problems ?

Thank you very much you all, I have read your forums for a while and I've got that far because all the information you guys share here.
Thank you

Last seen: 10 years 2 months ago
Joined: Apr 12 2008 - 02:49
I was playing with the screen

I was playing with the screen while trying to boot different linux distros and saw that using the mini-vga to VGA adapter doesn't help much as the main screen still gets the console messages and the external would load the graphical but only after a long while wait and all that I've got was a mouse pointer as I needed to pass boot parameters and I could barely ready the main screen.

So with mac OS X I could finally get real stuff out of it and now I know the machine works.

I'm about to order the inverter and play with it. But I'm unsure if there is a way to test the light-bulb, so reading around I've found a guy who recommends using a multimeter with Hz capability. As I don't have a multimeter for Hz I will order the new inverter and see what happens.

I may try checking compusa for a PC CFL kit but I don't know if I can just stick any CFL into any inverter.


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