Acer AX3400G-U4802

Your Acer is a slim case & unless you bought a low profile graphics card, it also wont fit in your case.
Did you buy a low profile graphics card?

Since this is a SFF case, I think that the PSU is either proprietary, or is a mATX PSU.

Well I did get a low profile card I made sure but what's proprietary? I'm new to computers.

Well Ive been visiting websites that claim they have a psu for it but most I see are boxes opposed to my rectangular psu

Proprietary means "custom made for" and will not fit for others.


Please put the link & we will help check. & it will also help if you can give the dimension of the PSU in your case. If you can not find it in the specifications, do actual measurement and post it here.

Well I can't exactly measure but I opened up my case and I have a liteon ps5221-9AB.

Maybe this one will fit:
http://www.newegg.com/Product/Product.aspx?Item=17-151-...
The Dimensions are 6.9" x 3.3" x 2.8".

I looked up my psu and it looks weird but it said 20 x 9 x 5,2 mm

Yeah... that's weird. Maybe it is cm? If cm it will translate to: 7.87 x 3.54 x 2.0 which is more reasonable. But I think its better for you to do actual measurement to be sure.

What do I use to measure?

A straight rule or tape measure. Preferably in Inches. You need to measure the height, length & width of your PSU to compare with the one I posted.

Can I buy a new case and put my pc into it?

Yes, you can.

But I guess it is more trouble than just replacing the PSU. You need to unplug all the PC case connectors (HDD & power LED's & power button, reset button, speaker, mic ) from the motherboard. And after your install the motherboard to the new case, you have to connect the HDD & power LED's & power button, reset button, speaker, mic of the new case to it. That is quite challenging if you are new to PC building.

But if you have a friend who can help you, a new case will open a lot of new upgrade options for you like bigger PSU, more powerful graphics card, etc...