Resolved 2017 iMac black screen on startup (boots)

[tripodbristol]

Hey everyone I'm looking for some advice/help...

Long story short I just took delivery of a new iMac (couldn't wait any longer.)

I opened up the RAM at the back - took one 4GB stick out - photographed it - put it back in.

(I photographed it to try and buy more of the same brand.)

Now EVERY time I boot the iMac there is a 30 second delay - presumably whilst it checks the RAM.

So I turn it on - 20 second black screen - then it boots as normal.

Any idea how do I stop this?

I've tried: PRAM, CMS and choosing the new startup disk.

1TB SSD, 4.2Ghz i7, 27", 8GB original RAM (no RAM added yet.)

Thanks in advance!
[doublepost=1530170663][/doublepost]Resolved - unplugged peripheries (an external SSD) - works fine now

 

[arncalars]

Are you sure you replaced the ram stick firmly enough and in the same slot.
If I remember correct, they are read in pairs and not beside each other. The four slots are paired 1,3 and 2,4.
Hope that can solve your problem.

Ups...I see you have solved the problem, but peripherals shouldn't be a problem.

Regards Lars