Need help Troubleshooting iMac

[raf051888]

I'm working on an 21.5" early 2006 iMac for a friend. He gave it to me with a bad hard drive which I replaced with a WD Caviar Black 500gb drive. However since the replacement, I have not been able to get any video from the iMac. I've tried with the iMac screen and the corresponding adapter. I'm wondering what the issue could be?

My thoughts so far:

1. Power supply - I'm not getting anything at all. The Led does not glow when plugged in, however the Mac appears to be booting correctly. [can't say for certain no video].

2. Video Card since - no getting any output.

What I have tried:
1. Reseating cables several times over.
2. Reseating the ram.
3. Putting the old HD back in; this still doesn't show any video.

I've worked on a Mac Mini before and work in hardware support on PCs, so I do know my way around. However, I'm pretty stumped with this issue. Any help / suggestions will be appreciated.

 

[miles01110]

Did you remember to re-connect all of the internal cables when you switched out the hard drive?

 

[raf051888]

From a quick glance over everything appears to be reconnected. I'll go back through the tear-down guide to make sure I didn't miss anything. Also, I am checked this while the iMac is partially disassembled [no iSight or Mic connection], I didn't want to have to take everything apart again.

Edit.... Just checked, I am connecting the everything.

 

[raf051888]

Bumping this, hoping someone can provide some assistance.

 

[chris98vf]

it's easy to F up a zif connector or pinch a cable or even just not seat it correctly. Go to www.ifixit.com and look at their repair guide for your model and see what you may have missed. It can't hurt to take it back down and retrace your steps.

Good luck!