After using third party software on my dual 1.8ghz Powermac G5, I had to force shut down by holding down the power button because the computer had completely frozen up. When I pressed the power button to turn the machine back on, there was a flash and a loud explosion from the computer. The G5 no longer boots, and is completely unresponsive. Any ideas as to what happened? Is there any way to fix this, or do I need a new computer?