iMac mid 2017 model was working perfectly fine, was stored in original box in a bedroom for 6 months. Today I powered it up and the screen stayed black.
iMac certainly powers on, as I can hear a start up sound and the fans are spinning as they would normally do.
PRAM, SMC were reset, also turned on the computer with ram boards disconnected. So far no luck.
any suggestions?
Please give AppleCare a call, it is possible by not using it for 6 months you allowed the PRAM battery to go dead. AppleCare will be able to help you out. However before calling please read and follow the steps in If your Mac won't turn on - Apple Support
My mid-2017 27-inch did that a couple of months ago and an SMC reset fixed it.
How to reset the System Management Controller (SMC) on your Mac - Apple Support
its broken get another one
iMac mid 2017 screen stopped working after 6 months of no use
