Power cut / surge changing boot order?

[gofes]

Hello all.

During the crazy winds we seem to have here at the moment we had about a 10 second power cut.

When I went to turn my computer back on all I got was the blinking _

Checked all the setting in the bios, and some how my boot sequence had changed to a random hdd with little on it. (I've got 3 hdds for storage and a sdd with the OS)

Is this a thing? Is there anything else I should check? Other than buying a surge protector!

Anyway I'm turning my PC off now until this is over.

[Lucio]

It could be that your BIOS is corrupt as a result of the surge, and it may be worth doing a factory reset on it just in case there's other issues that you haven't noticed.

[peterb]

It is unlikely that the BIOS (held in ROM) itself is corrupted, but it is possible that a power disturbance might corrupt the CMOS (volatile memory and battery backed) where BIOS configuration settings are stored. The CMOS also holds the system Real Time Clock - was that corrupted?

If you intend leaving the computer powered down during a period of unreliable mains power, unplug it from the wall as there are still some maintained supplies to the motherboard even when it is powered down.

A good power supply should give some protection against surges and voltage drops in daily use, but for protection against brownouts or larger surges, a UPS is probably a better option.

[DaveLEL]

It is possible that the problem is the battery used to maintain the CMOS memory and the real time clock (RTC).
Unless you turn off the computer at the Mains, there is a 5V Auxiliary supply present at all times, and this is used to power the CMOS memory and the RTC, along with the Ethernet interface.
The battery is there to provide power to the CMOS memory and RTC when the mains power is off - be it a power cut or the computer being turned off at the mains.
The battery normal lasts at least 3-4 years, but have seen some fail after only a year.

Not used that often but the RTC clock has the ability to turn on the PC at a set date & time, and the Ethernet port is active even when the PC is "off" giving wake on LAN capability.

Dave

[ik9000]

mine used to do that all the time, without a power surge but if the machine didn't shut down properly and I had to hard kill it via power switch. Had a weird habit of not sleeping/waking from sleep properly. I think it was porbably due to the SSD being too full to receive the swap file after I boosted RAM to 8gig... but i was having to reset the BIOS to AHCI, correct the boot order and all sorts on a regular basis.