I have an MSI RS480M2-IL motherboard which has a 24-pin power connector and an Antec True 380 PSU which has a 20-pin power connector cable. The manual says that it will work with 20 pin power though. With everything correctly connected, I push the power button and the Power LED lights up and all the fans (PSU, CPU, and front and rear fans) start to move for less than a second and then shuts down. I push the power again and again and it does nothing. If I unplug the power from the mobo for about 30 sec and reconnect it and push the power again it will do the same thing where everything starts to start but doesn't.
I put that psu in another computer. When I pushed the power button, the fan on the PSU started but nothing else was going on. The fan for the CPU didn't start. It was putting power through all the cables though. I tested it with a multimeter and connected it to a hard drive. The hard drive started spinning.
Thanks in advance.