He pressed the power button.
: Other listings with this marking feature the LGA 1155 socket, commonly bundled with CPUs like the Intel i5-2300 or i3-4330 . Intel Desktop Board 21 B6 E1 E2 Er
User suspected dead CPU. However, swapping CPU gave same result. He pressed the power button
When working with these legacy boards, users frequently encounter BIOS POST (Power-On Self-Test) codes or beep codes. If your board is failing to boot: List of Dr Debug BIOS Codes - Level1Techs Forums Intel Desktop Board 21 B6 E1 E2 Er
Because these boards are often pulled from office-grade machines (like older Dell or HP units), they frequently appear on secondhand marketplaces for affordable prices, typically ranging from depending on the included components.