|The noises you were hearing were probably caused by the cheap bearings in the power supply's fan being badly worn. It's likely that fan is either spinning too slowly or is no longer spinning and the power supply's components have overheated to the point that the power supply's circuits have failed. |
If you had replaced the power supply's fan shortly after you first started hearing those noises, the power supply probably would not have failed.
Sometimes a power supply damages something else while failing, often the mboard.
If you can borrow a power supply from a working computer and connect that to your computer, try that before obtaining another power supply.
If the orginal power supply has failed, you can usually replace it with any decent quality standard sized standard ATX PS with the same wattage capacity or greater.
Standard (PS/2) power supply size - 86mm high, 150mm wide, 140mm deep, or 3 3/8" h x 5 7/8" w x 5 1/2" d , or very close to that, though the depth can be more or less for some PSs.
Don't buy an el-cheapo (in quality) PS.
See response 3 in this: