2015 5k iMac Screen problem

[SCMedic]

Hey guys-

Swapped an SSD into my 2015 27" iMac and when all was out back together the screen doesn't work. External display works fine. I didn't reseal the screen yet while I tested it. Pulled it and checked that both cables were seated properly and they appear to be.

Not my first computer work, and I was very careful when removing and installing. Any ideas?

 

[ryguy92000]

Be sure to do an SMC and PRAM reset after opening the display. Sometimes the board needs to be reminded to turn on the display. If still nothing Look for the diagnostic LED's on the main board, they are sometimes covered in tape. Look for at least 3 LEDS when the machine is on. If you see 4 then you likely damaged the LCD somehow.