View Full Version : Apple PowerMac G4 Problem - No video

8th February 2014, 05:48 PM
I was given a Apple Power Macintosh G4 500 (AGP) that was about to go to landfill. My first Mac!
Specs: Power Macintosh G4 500 (AGP) Specs (Power Mac G4 - AGP, M7629LL/A*, PowerMac3,1, M5183, 1843) @ EveryMac.com (http://everymac.com/systems/apple/powermac_g4/specs/powermac_g4_500.html)

It powers on (chimes, green light front of case, red light on motherboard) but there is no video signal is going to the monitor (Monitor works fine connect to a PC).

Also the USB mouse flickers on for a split second then goes out, USB keyboard doesn't light up caps key when pressed (Swapping between USB ports gives same results). Both peripherals work fine on PC.

Two video cards in machine (Both ATI, One a Rage128 with a VGA port, the other I can't tell but it has a VGA port and DVI port). I've reseated both. Checked for dust. Tried VGA port on both still no signal.

I've reset (pressed) the CUDA/PMA button also. No difference.
Any ideas please? Thank you.

8th February 2014, 08:20 PM
Hi Herculoid,

welcome to the forum - you actually don't need a video card to boot a Mac, so unless you think it's booting to desktop I suspect something else is up with the machine. The first thing that comes to mind is bad RAM, so I'd strip it down to a single stick of (known good) working RAM, single video card. Also do a PRAM reset for good measure.


Dog Knight
10th February 2014, 11:40 AM
What Byrd said.

11th February 2014, 05:47 PM
My gut instinct suggests powering it on with just the one video card.

14th February 2014, 12:25 AM
Thanks for the suggestions. I tried the video cards on at a time. Didn't seem to make a difference. Then I removed a stick of memory and at the same time reset the PRAM (again). The video came through and the start up screen appeared! Also the USB keyboard and mouse came good. So maybe it was a loose memory stick? I managed to work out how to reset the password from the command prompt so I'm in and exploring the new world of OS X (Well an old version but you got to start somewhere)!

Thank you for your assistance!

18th February 2014, 06:26 PM
I'm very glad to hear. I hope the old machine provides useful.

19th February 2014, 09:19 AM
Great to hear it's going - cheap RAM sticks always go bung at any time. You should be able to max out the RAM very cheaply.