Aman_37 :
CPU temp 69-71°C and mobo 83°C Using approx 3 hours only
Weird thing is the motherboard is hotter than CPU. It may be any false sensor reading. Verify the temperature is same you got if you check in different tools like BIOS, HWmonitor & Speedfan.
1. Check all the fans including Stock cooler fans are running with good rpm(look in the BIOS).
2. Open the side case and leave it for a while, if the air flow is stuck withing the case this should eliminate it.
3. Replace the PSU and check
If nothing helps, you need to replace the motherboard.