Hello. My iMac G5 1,8Ghz appears to have some very weird problems. First, when I press the power button it will give the sound and eventually turn on the screen. It will boot but after 10 seconds, it turns off. So it still turns off at the boot screen with the logo! After a PRAM reset (1x), no luck. BUT, after a PRAM reset (wait for the 3rd restart) it boots! It boots into Tiger (new 2TB HD, fresh install). But, it shows these lines real bad as if the graphics card is failing. Also, this fades away until is normal! When doing a screenshot, is shows no lines. Perfect screenshot. At a reboot, it boots without doing anything. But when it is off for a while, same problem persists. What can be wrong? Facts: - Boots after 'all hardware reset --> alt+cmd+p+r till 3rd reboot" - New 2TB HD (old one crashed) - Weird Graphics card like issue at boot (when it boots) - Issue fades away till normal behavior - Screenshot shows no interferences. See pictures for further details! Screenshot was taken when heavy screen distortion occurred.