The iMac is Apple's line of all-in-one desktop computers.

6270 Questions View all

iMac 27" Late 09 shut down it self and restart! Shortcircuit?

Hi all, i've change video card of my imac (4670) with an 6670m. After one hour my imac shut down. Now when i want to power on, it turn on, no chime, black screen, and after 5 seconds shut down and restart itself (black screen, no chime sound). Without video card inserted, start and no shutdown, i hear sound chime but black screen (because not have gpu).

If i try to insert video card when it start without, and the imac shut down - Short circuit - . i've try 3 video card, but the symptoms is equal. Thanks all!

Answered! View the answer I have this problem too

Is this a good question?

Score 0
Add a comment

1 Answer

Chosen Solution

Have others successfully performed this upgrade? If not, there's your problem… only GPUs that have been used by Apple OEM on the logic board will work.

Check the diagnostic LED lights with the card in place - what do they indicate?

If this answer is acceptable please remember to return and mark it.

Was this answer helpful?

Score 1


Hi, and thanks for reply. The card is 6670m ati (iMac 21.5 2011), and is OEM certificate. The iMac is work perfectly before die, for a few hours. The leds state are with GPU inserted led1 and led2. Equal for GPU out (restart itself 2 Times).thanks


Add a comment

Add your answer

Paul Force will be eternally grateful.
View Statistics:

Past 24 Hours: 0

Past 7 Days: 0

Past 30 Days: 1

All Time: 214