BIOS & startup · high

How to fixPOST-CODE-15

POST Code 15 - North-Bridge Memory Init

What this error means

POST-CODE-15 shows up as a high-severity hardware BIOS/UEFI fault. Motherboard POST code 15 indicates a failure during early North-Bridge memory initialization. Commonly caused by memory compatibility issues, training timeouts on high-frequency DDR4/DDR5 sticks, or bent CPU socket pins. This can also stem from incompatible RAM specifications or speed profiles. The steps below are ordered to resolve this efficiently.

Before you begin

Save open work and back up important files. Note any recent driver or hardware changes. If Windows cannot start, use the startup guide first.

Work through these checks

0 of 4 complete
01Reset BIOS to defaults by shorting CMOS pins

Reset BIOS to defaults by shorting CMOS pins.

Use the instructions for your exact device and operating system. Check the manufacturer’s documentation before changing firmware, hardware, or system settings.

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02Use a single RAM stick in slot A2 to bypass boot check

Use a single RAM stick in slot A2 to bypass boot check.

Use the instructions for your exact device and operating system. Check the manufacturer’s documentation before changing firmware, hardware, or system settings.

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03Update motherboard BIOS using Flashback button

Update motherboard BIOS using Flashback button.

Use the instructions for your exact device and operating system. Check the manufacturer’s documentation before changing firmware, hardware, or system settings.

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04Loosen CPU cooler screws slightly and reseat CPU

Loosen CPU cooler screws slightly and reseat CPU.

Use the instructions for your exact device and operating system. Check the manufacturer’s documentation before changing firmware, hardware, or system settings.

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Possible causes

  • Incompatible RAM specifications or speed profiles
  • Incorrect memory voltage parameters in BIOS NVRAM
  • Bent CPU socket pins (uneven memory channel contact)
  • Uneven CPU cooler mounting pressure (warped board)