Just check these tips before you call computer technician save your time and money.
1. Check your Computer’s power cord is connected in properly on wall socket and the back side
2.Replace the power cord with new one
3.check your SMPS ( to check the SMPS short the green and ground wire together ground is default black wire, if the SMPS is working rotate the SMPS fan on the back side
4. Check your SMPS power supply is connected in properly on mother board
5.Check the power button cable is connected properly on motherboard
If you check all and everything is fine, this may the problem of motherboard kindly contact a technician