My PSU is upside down and only fits 3 screws

[entezio]

I put my PSU upside down so that the fan would be sucking in air from the bottom of my case because there's a vent there to suck in fresh air. Is that ok?

Also, there are like 4 holes in the back of my PSU but only 3 are fitting with the case, the fourth hole doesn't match with anything. I screwed the 3 in and it's pretty sturdy but I just want to make sure if it's fine like that

 

[nukemaster]

A power supply over a vent is not an issue, Many cases have extra holes to allow all 4 screws to be used.

Worst case as long as the power supply is not able to move, I think you will be ok.

What case is it anyway?

 

[entezio]

A power supply over a vent is not an issue, Many cases have extra holes to allow all 4 screws to be used.

Worst case as long as the power supply is not able to move, I think you will be ok.

What case is it anyway?

rosewill challenger atx mid tower
and my psu is the antec 620w atx12v

also a tiny part of the back of the power supply where the air comes out is covered by the case

 

[nukemaster]

If it is just a small part covered it will not hurt you.

If you look at the case power supply mount, it seems to have 2 SLOTS for screws. One of those should line up with the missing screw.

EDIT.

Adding an image, this should allow it to mount either way.

EDIT EDIT
redid the image to make it more easy to see.

 

[entezio]

If it is just a small part covered it will not hurt you.

If you look at the case power supply mount, it seems to have 2 SLOTS for screws. One of those should line up with the missing screw.

EDIT.

Adding an image, this should allow it to mount either way.

EDIT EDIT
redid the image to make it more easy to see.

omg thank you so much, my psu was still able to move up and down because of that one screw but I fixed it and now it's nice and snug
thank youuuuuuu

 

[nukemaster]

My Antec Nine Hundred and Fractal R2 is setup similar to that.

I think it is a standard way to ensure the largest opening for the power supply, while allowing it to face either way.