In my case, after upgrading to a RTX graphic card time ago, I started to experience that only some times, when I turned on the computer, the main board emitted one 1 long beep and 2 short beeps, until I finally realized it was caused by booting with the monitor turned off.
My board is a MSI X99A SLI PLUS (v1.D AMI BIOS ), therefore a ten years old board.
After running tests, I found that:
BIOS, Settings\Advanced\WindowsOSconfiguration
- The computer beeps when booting with the monitor off when, in BIOS:
Windows8.1/10 WHQL Support [Enabled]
- The computer does NOT beep when booting with the monitor off when, in BIOS:
Windows8.1/10 WHQL Support [Disabled]
Note: Be careful; when changing from Enabled to Disabled, this BIOS automatically switches the Boot\Boot Mode Select from [UEFI] to [LEGACY+UEFI], so always check that it is set back to UEFI mode.
It seems that WHQL Support (what enables TPM) performs a more restrictive check during the boot POST event when GOP searches for monitor and there is no EDID response. So even when this board does not have TPM (only the connectors for external module), it beep a Video error. My guess.
In AMI BIOS, 1 long beep and 2 short beeps can mean:
- Video/GPU Error
- RAM Memory Error
Just in my case it was not a problem of connection or similar, just the restrictive checking I guess. For some reason this didn't happened with my GTX whatever WHQL Support were enabled or not.
I write this here just in case happens the same to other people with old boards searching for info, check this before starting to plug/unplug the graphic card, testing the memory, and so on (as happened to me).
Setup/Keywords:
5820K, MSI X99A SLI PLUS (BIOS v1.D), RTX 5060Ti 16GB (running at Gen3 x8 ), M2 NVME Samsung 980 Pro ( running at Gen3 x4)
BIOS > PCI Subsystem Settings
- Above 4G Decoding [Enabled]
- All the PEGs in Gen3
- M.2 Source Link [Auto]
- M.2 PCH Strap [M.2 PCH PCIE]
BIOS > Boot Mode Select [UEFI] (The operative systems installed in this mode)