Hi,
I have a 27" iMac (2009) I am working on. The problem started with the system booting to the apple logo and rotating icon below, just before you would expect to see the login screen it would either go to a black screen with pixels or a purple and black screen, but definite into shapes fitting like teeth.
It also did this when booting to the OSX disc, would not get to the installation screen, again display issues. I have done the SMC & PRAM methods and also disconnected the hard drive just to be sure.
All four diagnostic LEDs would light up. I opened the system up to check the connections to the LCD and PSU. All were fine, but then I had no display at all upon boot up and now only two LEDs lit up, which I believe shows it is no detecting the GPU?
I just wondered if anyone could shred any light on what the issue could be. Is it worth get a replacement GPU, or is it likely to be other issues? Finally, I cannot be sure exactly which model of iMac I am working on, is there an easy way to find out. I presume checking the motherboard will tell me.
The iMac is aluminium with a black back panel.
Thanks again to anyone who can help.
I have a 27" iMac (2009) I am working on. The problem started with the system booting to the apple logo and rotating icon below, just before you would expect to see the login screen it would either go to a black screen with pixels or a purple and black screen, but definite into shapes fitting like teeth.
It also did this when booting to the OSX disc, would not get to the installation screen, again display issues. I have done the SMC & PRAM methods and also disconnected the hard drive just to be sure.
All four diagnostic LEDs would light up. I opened the system up to check the connections to the LCD and PSU. All were fine, but then I had no display at all upon boot up and now only two LEDs lit up, which I believe shows it is no detecting the GPU?
I just wondered if anyone could shred any light on what the issue could be. Is it worth get a replacement GPU, or is it likely to be other issues? Finally, I cannot be sure exactly which model of iMac I am working on, is there an easy way to find out. I presume checking the motherboard will tell me.
The iMac is aluminium with a black back panel.
Thanks again to anyone who can help.