iMac 27" 2009 Display goes off randomly Need a hand figuring out voltages please.

brooke.j

Member
iMac 27" 2009 Display goes off randomly Need a hand figuring out voltages please.

Not sure if this is off topic but I have an iMac that I've changed the power supply, Backlight board and V sync cable. Still keeps randomly going black. External display works just fine. Crazy thing is when I plug in a regular HD it doesn't have the issue. But when I plug in any SSD it does. Randomly goes black when booting from external USB too. Before I buy a new LCD for this can anyone help with some readings on what I'm supposed to have coming out of the LVDS and the power supply to the Backlight board .. and what voltages I should be getting out of the Backlight board. I don't have a schematic for this one unfortunately. Thanks in advance. Just trying to figure out how to test those components so that I don't end up spending a bunch of money and not get the right part the first time.
 

brooke.j

Member
Ok Weirdest thing, this might be classified under not an actual fix but I was just taping the SSD that has metal enclosure into the back of the iMac while I was working on it instead of mounting it in a mount like a normally do. For some reason I thought maybe there is some grounding issue. Not sure if this actually fixed it but I put the SSD into a mount which separates it from the chassis of the iMac and now it's working. Don't know but I hope it works for the rest of my testing.
 
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