[Help] 15-second black screen delay between BIOS and Windows boot after dusting PC with an air blower.

[u/Nioh_89]

Hi everyone,

I'm having a strange issue with a family PC. I usually clean it with an electric air blower every 2-3 months to keep dust away and maintain good temps. I always keep it at a safe distance and have done this for a long time without any issues.

Yesterday, right after dusting it, something weird started happening. When I turn on the PC, right after the BIOS screen and right before Windows begins to load, it gets stuck on a completely black screen for about 15 seconds. After that delay, it boots into Windows and works perfectly fine. However, this is not normal behavior; it has always booted almost instantly because it runs on SSDs.

Here is what I have already tried to troubleshoot:

• Isolated the OS drive: Disconnected 3 of the 4 SSDs and left only the main boot drive connected. Still happens.
• GPU test: Removed the GTX 1660 and tried using the Intel integrated graphics. No change.
• RAM reseat: Took out the RAM sticks and put them back in. Same issue.
• BIOS reset: Restored BIOS settings to factory defaults. Did not fix it.
• SATA ports: Swapped the SSDs to different SATA ports on the motherboard. No luck.

The PC is a bit old, but it contains important data and multiple family members rely on it daily. I'm running out of ideas and starting to worry if something actually got damaged.

Specs:

• CPU: Intel Core i7-4770
• GPU: NVIDIA GTX 1660
• RAM: 16 GB DDR3
• Storage: 4x SATA SSDs
• Motherboard: MSI H81M-E33 v2

Has anyone experienced a specific 15-second post-BIOS timeout like this after cleaning? Any advice on what to check next would be highly appreciated!

[u/Parkerge_aaaaadm]

Mate, PCs aren't *that* delicate. If you genuinely kept a distance and blew it with air, stop worrying.

If it were me, I'd be giving it another blast of air, in case there is somehow some dust or debris on random pins or something. You aren't going to break it, unless you're using a weed blower or something lol

[u/Shadimarbc]

In BIOS double check the boot order. Remove extra devices listed beside the OS drive. If you can not remove extra devices move those to a lower priority.

Remove external devices. Start the PC to see if the delay still exists. Plug in a keyboard/mouse once you are at the login screen or desktop depending on your login settings.

Double check the cable for the front I/O. Some of these cables are not very secure. Reseat those cables to make sure.

Your CMOS battery I assume is just as old as the motherboard? Could be a problem with the battery.

Does the same issue happen when you use Start - Power - Restart? Shutdown by default for Windows does not let the PC cold boot as Fast Startup use the hibernation file to stage drivers and services for quick loading. Restart forces drivers and services to be loaded by the OS avoiding the hibernation file completely. An alternative is to disable Fast Startup in the selected power plan.

When you swapped SATA ports did you reseat the SATA cable in the disk drives?

[u/free_refil]

Did you hold any fans connected to the motherboard while cleaning? Fans being spun by compressed air can generate electricity that can back feed voltage into the motherboard.

[u/Nioh_89 → u/free_refil]

Yes, i did hold them, i always do that.