Replaced HD with SSD, now get startup chime but only black screen
I replaced the internal HD with a 1TB Crucial MX500 SSD and used the OWC Complete Hard Drive Upgrade Kit and NewerTech AdaptaDrive to complete the upgrade. This was the fist time I opened my iMac and I was careful to follow the steps from both iFixit and OWC. Got every thing back together but when it boots I hear the startup chime and only get a black screen and a very loud fan (never heard it that loud before). I've tried the following keys at startup:
- Option (Startup Manager, with a bootable USB thumb drive plugged in)
- D (Apple Diagnostics utility)
- Command-R (built-in macOS Recovery)
- Option-Command-P-R (reset NVRAM)
But the screen never comes on. The new SSD should be fine — I used Carbon Copy Cloner to make a bootable clone of the previous internal HD and booted from the cloned SSD using an external USB enclosure to make sure it worked.
Is there anything else I can check before I pull the screen off again and start checking connections? Once I've done that, what should I do to make sure it boots before sticking the screen back on (don't want to keep buying adhesive strips)? Thanks!