2 USB ports maybe bad

My computer has 8 USB ports total,
4 in the back on the bottom
2 in the back on the top
2 in the front.
I had my mouse and keyboard in the 2 top in the back.
On occasion I lost my mouse indicator but it came back.
This also happened to my keyboard, when it did I had no light on my keyboard.
I'm now using a hub for them.
Can you give my any insight as to what I am going to find when I get into it ?

Fortunately I ordered a USB hub before this all happened, It's working fine, however I'd like to have the computer in shape.
Thanks.