iMac 2008 - El Capitan stuck at install

[Madsls]

I have an older iMac 2008 where i dont have acces to the desktop any more, and need to reinstall El capitan again.

Im using bootable USB with El Capitan from Apples website.

My problem is when im booting it from the USB, starting to Erase the HDD/SSD, and start install it going far, but at the end just before you need to type ind Username, password "welcome screen - Choose your location", its going stuck, and "Voiceover" is talking and i can just use ESC or the arrows keys to let the Voiceover speak, but nothing else happen, even after 1 houre.

I have tried to downgrade to Yosemite, and same happen stuck.

I had tried to use the original HDD, and changes it to an SSD, same happen, i have tried to swap the Ram, to see if there should be any Ram problem, NVRam reset, Date changes, and i have talk to Apple support but no help. Even i have search alot about some errors, and watched 100 of Youtube videoes but same error/stuck. - I cannot use the Recover mode, and download from recoery internet, it wont work eaither. So thats why i use Bootable USB because its let me go far then that way.

And im starting to giving up! I have allmost used 24 houres on it! Reboot, reinstall, install, delete, changes hdd and so on.

Any one maybe know what to do?

 

[Madsls]

Okay i figuriet out of a problem, i can move arround with the mouse pointer, but i cannot click on any thing. And it allways happen, but when i click on something and wait like 10 min so the screen are going to sleep, and touch the keyboard or mouse again, its turn on and the images has changes, and i can do the same again, so mouse pointer no problem but screen freezing