The PowerMac G5 is a desktop computer first produced in 2003 by the Apple Corporation. This guide will review the repair process of an Apple PowerMac G5 model number A1047 EMC 2061 from 2004.
It was discontinued in 2006 as part of the Intel switch first to developers then consumers.
Sounds like a blown or loose video card. Check that it is properly seated. If it is you could see if you can reapply the thermal paste on card if that doesn't work see this.
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