Imac only Starts without GPU

[manuel_99]

Hello everybody,
I had bought an Imac mid 2010 I3 with a defective graphics card. So far so good, arrived undamaged and was in top condition. Inside, however, I found the graphics card loose. Didn't Wonder top much, because the device was supposedly from a repair service, which found the graphics card defect. I first started the Imac when it was still assembled and the Chime was coming, but no picture. So I Tried with the new graphics card and everything assembled-nothing is working no more. No chime, only the fans turn up. Only status LED 1 is on. After constant measurement and headache, graphics card removed and started - LED2 comes on again. Is it the logic board? Or do you still have ideas? I'm grateful for any help and don't just want to go blind and buy a logic board. Thank you in advance for your help.

 

[USB3foriMac]

Best describe what 'new' graphic card you are using, and how you know this is working.
So now let us assume the graphics card is indeed working (e.g. in another 2010 machine).
- It could be inserted wrongly: do the entire procedure again, and make sure the graphic card does not cause short circuits towards the CPU cooler, logic board holder, log board components, etc. This appears to be the most likelt reason according to many reports in the graphics card thread.
- it could be the logic board: something wrong with the card slot, for example. It would be near impossible to verify this, but chances are low that this is really the problem.
- it could be the power supply: nough power to power the board, but not when graphics is plugged in. So if you have a multimeter, measure the outputvoltage at the supply while the machine is on. Take care not to electrocute yourself, as there is high voltage (240VAC, 360VDC). So far, there have been only few reports of this kind, so it seems less likely that this is your problem.
- it could be an incompatibility, e.g. if the graphics card iis 'newer' than your system, e.g. BIOS/EFI incompatibility. You should try the model of graphic card the 2010 models were initially delivered with.

Best if you have a second system to test the graphics card as well as the power supply. That would pretty much leave the logic board.

 

[manuel_99]

Hi, the Graphics Card is a Nvidia Quadro K2000M. Its Not flashed yet, because I wanted to flash It within the Mac via Windows, wich is already installed. I now have another Problem, i also Upgraded to an I7 870 and this CPU doesnt recognize the Graphics Card anymore. If I Reinstall the old I3 everything is working flawlessy. With the I7 only LED 1 and 2 Light Up. With the I3 1,2 and 3 Light Up. I've read that the I7 is compatible with this Mac isnt it?

 

[r6mile]

Hi, the Graphics Card is a Nvidia Quadro K2000M. Its Not flashed yet, because I wanted to flash It within the Mac via Windows, wich is already installed. I now have another Problem, i also Upgraded to an I7 870 and this CPU doesnt recognize the Graphics Card anymore. If I Reinstall the old I3 everything is working flawlessy. With the I7 only LED 1 and 2 Light Up. With the I3 1,2 and 3 Light Up. I've read that the I7 is compatible with this Mac isnt it?

Pretty sure you can't put an i7 in a 21.5 2010 iMac, it draws too much power. The highest for that machine is the i5 3.6Ghz I think, which was the top specced 21.5 at the time.

 

[Ausdauersportler]

There is a complete thread about changing the GPU in iMac 2011 - worth to take look at..