My iMac G4 17" flat panel (10.3.9/800MHZ PowerPCG4/768 SDRAM) goes very dark with the keyboard plugged in. An 8 blade daisy icon appears & when I check the display settings the brightness button is all they way to the left. It doesn't stay to the right (& the screen is bright) unless I unplug the keyboard.... Can someone tell me what to do to fix this problem, please? I know the machine is 10 yrs old & had a new hard drive 3 yrs ago, but it works well & I use it for all mu digital photo & video work...... If you can help - thanks.