youtube link

watch?v=my0s7cxKJiE

video shows my problem turn power on and elevator still shows as low power

I remember having the same problem a few years ago. Unfortunately i forgot what it was but i missed some item or activation on some terminal somewhere. Just keep looking around and post the solution.
This is not a bug.

i did same level on doom 3 version and i got past it

its a bug

When you restore power, that GUI should turn green allowing you to call the elevator. If you push the button before restoring power, then you won't be able to push it after you restore power.

well then its a bug isn't it? and how save games work in doom 3 bfg i will need to restart the whole game again

You know you can make a save whenever you want right? I save after every major battle.

i know but i saved again just before the elevator

You can have multiple saves. Not just the quick save, which is what I assume you mean.

no i don't mean quick saves but still it something should be looked at when they do a patch