won't startup

We have a 2010 iMac that wouldn't update to El Capitan so I decided to by pass it and make USB High Sierra and install. I booted from the USB and installed and erased the HHD. I chose the HDD I erased. It seemed to work but towards the end I reboot and a flashing fold with a "?" popped up. I...

Ya, I really messed up and let Macbook get down to essentially no space left and now can't start. I've tried the safe start, while holding shift after starting but with no luck. The computer starts up fine and get the the sign in but makes it about 80% of the load bar and it shuts down/goes...

Hi, So I tried to do a little research before I posted anywhere but I've not found many with the same issue as me. I recently was having problems with the screen going black / off after working for a while. I was working with it on the lowest brightness as any higher would just make the screen...