Lcd not working after rebuild

Added more pictures I’ve been into computers for over 35 years windows 3.1 then win 95 building fixing and helping people i won’t touch alienware pcs and i don’t think i will be touching another imac i upgraded this from a i5 to a i7 2600s re pasted added ssd and more memory it works ok with a external monitor purchased the OWC sensor cable but fans still on full

@davidmitch91997 - Mac’s are a different beast for sure!

While hard to tell as the images are hard to see the cable end does look like it lost its edge of one or two pins. The socket looks a bit distorted the far left/right detent sockets are bent up so the cable pins can’t secure it fully. These are easy to damaged and often if you bend them back they snap so don’t push it a piece of tape is about all you can do across the flat part of the connector.

For now, you’ll need to replace the cable if it’s indeed damaged. It should mirror the other side. This could explain why SMC is pushing the fans, after replacing the cable let’s see where you are. Here’s the needed part iMac 21.5" Display Port Cable