Look at the weirdness of the PowerEdge r430

I'm using a PowerEdge r430 and I'm currently unable to use a server computer due to a strange phenomenon I've never experienced before.

The strange phenomenon is as follows.

- Server power is maintained.

- The monitor is not outputting anything (unplugging the cable will say no signal, and when connected, the monitor power light will turn orange. Blue light when normally output or disconnected)

- In this state, pressing the server's power button does not shut down. The cable must be disconnected.

- After disconnecting and reconnecting the cable, the power supply LED turns green. In this state, the server does not turn on when the power button is pressed. (Do not wait for a minimum of 2 minutes and a maximum of 1 hour before pressing the power button.)

- If you disconnect and reconnect the power cable for about 2 to 3 hours, it will turn on.

- The setup screen will output normally. Then, over time, the symptoms appear.

- I don't know exactly how long it takes for the symptoms to appear on the normal screen.

(After booting the window, symptoms appeared about 5 minutes later, and sometimes it was fine for a few hours on the CMOS setup screen.)

- If the symptoms appear, keep the power cable disconnected for 2-3 hours and then reconnect it.

- The symptom screen appears and then suddenly the symptom appears.. It repeats.

And in this symptom state, iDRAC access is possible (access from my pc, use iDRAC

- When checking the hardware status with the iDRAC8 connection, it appears that there is no problem. (In the eyes of beginners.)
- The web console function does not work "Power Off" or "Reset" with the iDRAC8 connection.
- The bios update function is possible.

How can I solve this problem?