My PC does not start, but the coolong fan turns or stops. And the state in which the fan continues to rotate has been resolved 2.

My sub PC is usually online for 24 hours.
I switched off the power 3 days ago and turned on today but it did not start.

Moreover, when switching on …

Push power button

Repeat until all the fans (power supply fan, CPU cooler, exhaust fan) turn around with the fern and stop

Press and hold the power button

Power off

This was my first symptom.
Looking at Google it seems to be a breakdown of the power supply unit.

Hmm … ATX power supply …
It is around 5,000 yen in the power supply 500 W unit …

Before buying a power supply unit, I had a suspicion.
I tried to doubt the button type battery set on the motherboard.

Previously I have the experience of exchanging button type batteries inside my main PC.

First, I removed the old button battery and discharged it for 1 day.
Next, I bought a Sony CR2032 battery.
Next, it installed so that fingerprints do not adhere to the button type battery.
And I turned on the power.

Push power button

All the fans (power supply fan, CPU cooler, exhaust fan) do not start with Fern

Press and hold the power button

The power is turned off at the judgment of the PC

Hmm? I feel that symptoms have improved since last time.

I removed the power supply unit from an available PC. And I built it in this PC.

Power on with the cover fully open

All the fans (power supply fan, CPU cooler, exhaust fan) do not start with Fern

Press and hold the power button

Power off

That means that it is not a malfunction of the power supply unit.

The next thing I thought was cleaning the memory unit.

Disconnect the power cord and press the power button to discharge.

I pulled out the memory from the motherboard, blown by air duster, and blown inside the slot of the motherboard.

Re-set and power on with the cover open!

All the fans (power supply fan, CPU cooler, exhaust fan) turned around with Fern and beeps “beep”

Since I pulled out the button battery, I got the setting request screen of the BIOS, but I went for a while at F1.

A startup screen of Windows 10 appears and it seems to be executing “automatic repair”!

It restored by automatic repairing for about 5 minutes.

Well, I learned that dust in the memory slot will cause failure.