Ok, to clarify, yes I meant the pins for power/reset/hard drive light, etc. On some name brand PC's, they use a special pin header that normal ones don't fit onto, flat ribbon cables, all kinds of weird hook ups. Luckily, you seem to be in luck as this model of acer uses a fairly standard pin hookup.http://www.manualslib.com/manual/232904/Acer-Aspire-X1920.html
There is the full manual for your motherboard. Click download at the top and enter the code to download it.
On page 76, you will see the pin out's at the bottom for the motherboard. Really, the only one you need hooked up is the power button but if you want the HDD light and power light to work, just follow the diagram. It shows the way the pins are, from 1 at the bottom, then 2 at the top, then the next row will be 3 at the bottom, 4 at the top, and so on. So for power it would 6 & 8 for the pins, so the power button from your new case, which would be labeled as such, you would plug that onto pins 6 & 8. If it doesn't work, try reversing the plug. Some plugs don't care the way they are, some do.