SF314-57 Unusually slow POST

Athwart · June 2022

I'm having an occasional issue when I boot the laptop where the time to execute the POST is significantly delayed i.e. the time taken after pressing the on button until the Acer spinning balls logo appears is usually only a few seconds but every once in a while it takes about 15-20 seconds. After the spinning balls logo does appear, Windows 10 starts in about the usual amount of time however inevitably my USB mouse fails to work with a Windows message that the USB device was unrecognised. The tablet still works OK & as far as I know, everything else is fine but I always re-boot soon after this occurs.
The only way to fix the problem is to do a hard shutdown by holding the power button until it shuts down. The problem reoccurs if I shutdown via Task Manager or Windows shutdown. I normally shut down via a hibernation utility and I have fast boot enabled.
I've done a Windows Memory Diagnostic with no problems being reported. The SSD volumes have plenty of free space and all show as healthy in Disk Management and no problems are reported by the Western Digital Extended Diagnostic test. Event Viewer doesn't show anything that seems relevant.
It's not a huge issue - the laptop is about 18 months old and it has only happened about 6-8 times but it has happened twice in the last 2 weeks. Maybe something is degrading with time. The only thing I can think of is a problem initiating the USB 2.0 port that I use for the mouse but I don't know if this happens during POST.
Has anyone seen this issue before and have a solution?

billsey · June 2022

There is a USB devices test during POST and if data coming from the device is garbled it might spend extra time retrying the initialization. It wouldn't be a drive issue as such since the filesystem isn't mounted before POST is completed and it's loading the OS. Can you get the symptoms to appear without the mouse connected? If you boot without the mouse then plug it in later does it sometimes take a while to be recognized? It will help a lot of we can pin it down to the port or the mouse itself...

Athwart · June 2022

billsey said:

There is a USB devices test during POST and if data coming from the device is garbled it might spend extra time retrying the initialization. It wouldn't be a drive issue as such since the filesystem isn't mounted before POST is completed and it's loading the OS. Can you get the symptoms to appear without the mouse connected? If you boot without the mouse then plug it in later does it sometimes take a while to be recognized? It will help a lot of we can pin it down to the port or the mouse itself...

@billseyThanks for the reply.
It's not really practical to test without the mouse connected since the symptoms are so infrequent. I have tried re-booting with the mouse disconnected. Once in Windows, when I insert the mouse dongle into the USB port it is recognised immediately with a sound and the cursor responding to the mouse.

Commodore_1995# · June 2022

I advise disabling fast startup in options back in the day. When fast startup is enabled, a file called hiberfil.sys is created. This file increases in size as you turn off the computer, because fast startup is a mixture of hibernation and computer shutdown, that is, the computer does not turn off completely. This may generate some errors during system startup. Most recent computers come with an ssd. Therefore, the startup difference between fast startup off and on, is minimal.

Athwart · June 2022

@egydiocoelho Thanks for your suggestion. I agree that there is negligible difference in boot times whether fast startup is enabled or not. I have disabled it.
However I think you're on the wrong track saying it relates to hibernation or hiberfil.sys.
The slowdown problem is occurring very early in the boot process i.e. before the Acer logo even appears.
If I do a cold boot re-start, the screen turns on but is black, then the Acer logo appears followed by the boot manager screen (I have set the bootmgr displaybootmenu to yes) then the boot into Windows.
If a do a resume from hibernation, the screen turns on but is black, then the Acer logo appears followed by the spinning balls then the boot into Windows.
Since the slowdown is happening before the Acer logo appears, I assume it is happening during POST &/or initialisation of the hardware devices by the BIOS. It doesn't appear to be related to the OS.
I think that @billsey is on the right track suggesting that it might relate to a problem when checking the USB port(s). Not a severe enough problem to produce any POST errors or beeps but enough to slow down the process.
Since the problem is infrequent, I can live with it.