imac cannot boot when ultra II 960 is attached internally

Hi There, I’ve just replaced my insternal CD drive on my imac (late 2009) with an ultra II 960gb. When I do a pram resert to detect to hardware it kills my system. The firmware or bios cannot detect the new ssd and it seems to kill the boot up process dead. I can’t even do any boot to safemode, boot in target disk mode - Anything. All I get is a white screen.

If I then disconnect the ssd the mac boots up again fine.

Anyhelp will be seriously appreciated


in that case i suggest contacting the ssd exernally to a computer to see if you can format it and then try it once more on the mac computer. 

if the drive is working fine on the other pc then the mac has an issue with ssds, if not then the drive is faulty and it needs to be replaced. 

I am having the same issues. Did you figue this out?

I am having the same issue on my 2009 Imac.   I can boot from a USB external enclosure, but not internally.  I don’t think the SSD drive is bad, but I do think there is a firmware update needed that may not be availabe for El Captain at this point in time.  I think it is time to consult with SanDisk because I think the firmware needs to support the slower 3Gb/s for these aging Imacs.

Solution:  Get the OWC Data Doubler and replace the DVD ROM Superdrive with it; leaving your original drive in place.   You will then be able to specify to use the SanDisk as your boot drive and this will work without need to update any firmware.