Greetings everyone! I have a late 2009 27" iMac, i7, 2.8Ghz (I think) and I am in need of some serious technical assistance 
I had a 125GB SSD drive in it, as well as a 1TB HDD, and my applications were pushing the SSD to it's capacity. I ordered a new SSD, thought "I'll just pop this in", so I made sure my backup was current, pulled the front panel off, took the screws out of the display, took the cables loose very carefully, and took the display out. Swapped out the drive, pretty uneventful. Put it all back together, being careful with the cables since I know that's a known issue.
Put it all back together, turned it on, held down the Option R keys, got the tone it plays when it boots up, no display. Nothing. Zero. Not even a blink of the screen.
Took it all apart again, unplugged all the cables, plugged them all in again. Nothing. Put the old SSD drive back in, nope, nothing. No display. Took it all apart about 6 more times, carefully checking each cable to make sure it seemed right.
Still no display. I can't figure this out at all.
There are 4 cables to unplug as far as I know.
One is a temperature sensor, one is the large cable that's zig zagged that hooks to the logic board and then to the center top of the monitor, one is about 8 pins and hooks to a board on the left hand side of the computer, and one is the vertical synch cable at the top. The previous owner had damaged that cable, but I was still using it. I ordered a new cable and installed that, and it didn't fix the issue. New cable, old cable, still no video.
Any suggestions on where to start to try to troubleshoot it. Prior to this, the computer was working just fine. I honestly unplugged 4 cables, took the monitor loose, swapped the drives out, put it all back together and it didn't work, so I'm really stumped.
Any help would be GREATLY appreciated.
I had a 125GB SSD drive in it, as well as a 1TB HDD, and my applications were pushing the SSD to it's capacity. I ordered a new SSD, thought "I'll just pop this in", so I made sure my backup was current, pulled the front panel off, took the screws out of the display, took the cables loose very carefully, and took the display out. Swapped out the drive, pretty uneventful. Put it all back together, being careful with the cables since I know that's a known issue.
Put it all back together, turned it on, held down the Option R keys, got the tone it plays when it boots up, no display. Nothing. Zero. Not even a blink of the screen.
Took it all apart again, unplugged all the cables, plugged them all in again. Nothing. Put the old SSD drive back in, nope, nothing. No display. Took it all apart about 6 more times, carefully checking each cable to make sure it seemed right.
Still no display. I can't figure this out at all.
There are 4 cables to unplug as far as I know.
One is a temperature sensor, one is the large cable that's zig zagged that hooks to the logic board and then to the center top of the monitor, one is about 8 pins and hooks to a board on the left hand side of the computer, and one is the vertical synch cable at the top. The previous owner had damaged that cable, but I was still using it. I ordered a new cable and installed that, and it didn't fix the issue. New cable, old cable, still no video.
Any suggestions on where to start to try to troubleshoot it. Prior to this, the computer was working just fine. I honestly unplugged 4 cables, took the monitor loose, swapped the drives out, put it all back together and it didn't work, so I'm really stumped.
Any help would be GREATLY appreciated.