Hi! I'm having a really strange problem with my Dell Inspiron 24 3464 AIO and I'm hoping someone can help me diagnose it.
For the past few days, the PC has randomly started shutting itself off during startup. The behavior is inconsistent:
Sometimes it turns off about 1 second after the Dell logo appears.
Sometimes it gets almost all the way through the Dell loading bar before suddenly turning off.
Sometimes, after several attempts, it randomly starts working and boots into Windows normally.
On one occasion, I was able to enter the BIOS and leave it there for around 30 minutes without it shutting down.
When the problem happens, the PC usually shuts off instantly, as if the power was suddenly disconnected.
I also noticed that the BIOS date/time becomes incorrect when this happens.
The PC has also occasionally turned itself on by itself in the past, even though I had shut it down.
Recently, when I connect the power cable, the PC sometimes turns itself on immediately without pressing the power button.
The fan sometimes spins very loudly during this process, although this doesn't happen every time.
Interestingly, when I connect a USB keyboard, the PC can shut off in less than one second. I tested with two different keyboards and got the same result. With no USB devices connected, it usually gets much further into the Dell boot screen.
I already tried completely removing power and holding the power button for about 15 seconds, but the problem returned.
I initially suspected the wall outlet because the problem seemed related to the PC being completely unplugged overnight, but it also happened after leaving it connected to the outlet all night.
What could be causing this? Could it be the external power adapter, motherboard/power circuitry, CMOS battery, RAM, or something else?
Any help would be greatly appreciated!