Tried to power my acer z3101 u4062 to on but it wont. Our pwer supplies 240 v . The sticker on the back of the computer says it has ratings of 110-120/220-240 Vac. The wires are properly wired in. Am i missing something ? Help

On the back of your power supply if you slide the switch to the voltage for your house (110V or 220V) and it still doesn't work, try the following:
1. Make sure the toggle switch on the power supply is in the on position.
2. This is important; is the power cord firmly pushed into your power supply? It can sometimes pop loose just enough not to make a good contact.
3. Last but not least, plug something else in the same wall socket your computer is plugged into to make sure there is electricity.

Many computer power supplies have a 120/240 input voltage selector switch. If yours has one, it would be visible on the back of the computer within a few inches of the power cord socket. Make sure it's in the 240 V position. If you applied 240 V with the switch in the 120 V position, you may have blown a fuse or worse in the power supply.

There are also "universal" power supplies, which are supposed to run on anything from 96 to 270 volts. Those would not have an input voltage selector switch.

That appears to be an auto sensing supply, replace it.