Black Screen on early-2009 24" iMac

[bobesch]

A few days ago I took my early-2009 24" c2duo iMac to the Office to get him connected to the office-network.
It's got Win10Pro installed and at home, everything worked fine.
In the office fans started to run on booting and continued to run nonstop at full speed, so I powered the iMac down and took it back home for further inspection.
All 3 thermal sensors (which might cause fan's to run full speed, whenver disconnected) proved to be plugged in. Some dust had to be blown out. Nothing else I could find (but that does'nt mean that much...)
After reassembling and pressing the bower-button, there is a booting-chime. PRAM-reset can be performed. I can hear the starting-chime of Windows. But screen stays pitch-black. A connected beamer (through mini-display-to-VGA-adapter) is indicating, there's no signal.
The hard drive can be mounted on another Mac through FireWire-TargetDiskMode connection.
Is it, the graphic-card died? Or anything else I can try ...?
Thanks for any help and suggestions. - I've already searched the iMac-subforum, but it's like looking for the needle in the haystack.

 

[Amethyst1]

Sounds like the GPU (which one is it, by the way?) may have given up the ghost. Can you remote-desktop into the box and see if it's still recognised in Device Manager?

 

[bobesch]

Sounds like the GPU may have given up the ghost. Can you remote-desktop into it and see if it's still recognised in Device Manager?

Trying RDP sounds a good idea! I didn't try it - I can't even remember the iMac's IP-address, and don't know, if there was a wireless-connection and by using LAN, the IP-adress would have changed anyway. And I don't know, if I had opened Windows for remote access on that iMac ... Oh, too many question-marks.
So for now, I've retired the iMac and removed the SSD. Hope it'll make the transition into another iMac without beeing cut off licence during that procedure (I've been once through this before, after I've opened the Win10Bootcamp-partition as kind of virtual machine within VMware Fusion ...
Currently I'm a both tired of screwing and reinstalling Win7/8To10Upgrade and all the necessary stuff...
Until the real thing comes along, substitute will be this c2d MBP from 2009, sitting on an mStand, attached with USB-keyboard/TPU-cover and USB-mouse (to keep the MBP clean from sticky fingers as a result of desinfectant and skin-care).


PS: but what, if I was able to RDP into the iMac? Would it be possible, the GPU is ok, given, that there has been no output through the mini-display port ...

 

[Amethyst1]

PS: but what, if I was able to RDP into the iMac? Would it be possible, the GPU is ok, given, that there has been no output through the mini-display port ...

I'd say that if the GPU doesn't even show up in Device Manager anymore, it would also point to it being dead. Did you try an SMC reset for good measure? (Disconnect power cable and hold power button for 5 seconds, reattach and power on.)

 

[bobesch]

I'd say that if the GPU doesn't even show up in Device Manager anymore, it would also point to it being dead. Did you try an SMC reset for good measure? (Disconnect power cable and hold power button for 5 seconds, reattach and power on.)

Ha, I forgot the SMC reset! When the fans were constantly in action I thought about that. But I did open the iMac first, checked the temperature-sensor cables, blew out all the dust and after reassembling the screen kept dark.
I fear, that I have damaged something during the cleaning ...
... and I thought, that couldn't be mended by SMC reset anymore. And I just forgot about it.