Help needed - Prodesk 490 G1 MT with i5-4590 - freeze on reboot

[frankvnk]

I encountered an annoying issue with my Prodesk 490  G1 MT running Windows 11 or Windows 7.

When i choose to reboot or, when the computer needs to reboot after installing updates, Windows shuts down properly but then the screen goes blank, the monitor goes into power saving and the mouse and keyboard are powered off. The fans are still running but the computer refuses to reboot.

The only way to get it back up and running is to power it down with the power button and switch it back on again.

Windows does not complain about an improper shutdown and boots normally.

As a test, i also tried Windows 7, the problem remains.

Additionally, i took following steps in order to try to resolve this issue, unfortunately without any luck:

1. Disable Fast Boot in Windows - The problem remains.

2. System check using chkdsk, sfc /scannow, hardware diagnostics - No errors - The problem remains.

3. BIOS update to the latest version - The problem remains.

4. Made sure all drivers were up to date and all Windows updates are installed  - The problem remains.

5. Used another keyboard, mouse and screen - The problem remains.

6. Complete reinstall of Windows, the problem already occurs upon the first reboot during installation. I did finish the installation in order to use a fresh system (quite annoying, i had to switch the system off/on manually upon each reboot).

7. New hard disk (SSD) - The problem remains.

8. New memory - The problem remains.

There is a solution that allows me to reboot the computer properly:

I have a Prodesk 490 G2 MT where an i7-4770 is seated. I put this CPU in the 490 G1 MT and a reboot is working flawlessly. I then tried the i5-4590 in the 490 G2 MT and the system reboots without freezing up.

So, using the i5-4590 CPU with the Prodesk 490 G1 (mainboard: MS-7860 V1.2) is causing this issue.

Is there something wrong with the BIOS microcode? Or is something else causing this issue?

Any help is greatly appreciated.