The tower wont turn on

Check your power supply. Most common reason for your problem is that the psu has died. Also near your main psu connection on the motherboard should be a little led light. If your board is getting a proper power connection/supply that light should be green. If not it will either be off or red. If it is green then the problem may be your motherboard. If it is red or off then it is most likely a bad psu. Replace with a compatible psu & you should be back up & running. Hope this helps.