iMac on reboot loop

[Porygon2z]

Hello, I'm new here.
All of a sudden my iMac turned off and then entered to an endless reboot cycle. The status bar under the apple logo only gets to almost half the line and then it restarts again. I've tried recovery mode but it doesn't do anything. I tried safe mode but when I do that it stays on a white screen and doesn't do anything. Using the cmd+v works and when it starts to show some things with "failed" it reboots again. Cmd+s also works but I haven't managed to fix with anything.
Don't know what to do.

 

[Fishrrman]

"Don't know what to do."

You can start by telling us about the iMac.
Which one is it?
What year was it made?
What size is it?
What version of the OS is running on it?

 

[Porygon2z]

"Don't know what to do."

You can start by telling us about the iMac.
Which one is it?
What year was it made?
What size is it?
What version of the OS is running on it?

iMac 27" mid 2011. i7 16gb ram, 3.4ghz, Sierra. 1TB HD.

 

[Fishrrman]

The drive could be failing.

Is the 16gb of RAM "original"? Or did you replace/add to it?
Sometimes RAM can cause problems.
Solution could be as simple as removing RAM, cleaning tabs, replacing it.