1 New SSD / RAM - no backup disk & black screen but have chime
I have had a lengthy repair starting with trying to upgrade to a SSD and upgrade the RAM. Somehow the motherboard got fried during that process. Just installed a different motherboard. Unit finally starts up; i.e. I can hear the fan spinning and after several seconds I hear a start-up chime, but the screen stays black; no apple logo. I have checked and the LED lights on the motherboard are all lit (except for the top / 4th one). I think this is happening because there's no OS installed on the new SSD, but I don't think I can do the internet OS install as I have a wireless keyboard / mouse that aren't paired to the computer yet which I think you use to initiate the OS download process. And not sure how I'd see what's happening if I try to make a USB bootable installer given that the screen is black. Thanks for any guidance!
Es esta una buena pregunta?
7 
3 
Do you have access to another computer and the old bootable drive?
- de Juan Garcia
The old HDD was having issues so I reformatted it. I do have a MacBook Pro to use.
- de Neil Harfert
Hmm. With the old one a simple partition. Clone to the ssd would have worked. I 'd look for a bootable image on line then. I know how to do it on a windows machine but not on a mac,. I upgraded my brothers (mac) HDD just copying and resizing the partition, surely you can do tnat on mac. But I can't tell you how (at the moment). If you need,. I'll research it.
- de Juan Garcia
Thanks. Would this be what’s causing the symptoms I’m experiencing? Also my keyboard and mouse are the wireless “magic” style - will the iMac automatically find the boot usb or so I need to source a different keyboard to use? Thanks again!
- de Neil Harfert
My last comment got lost in a system hiccup, I don eknow mac's. OS well enough to answer that, hopefully the boot image will turn the trick.
- de Juan Garcia