Failure to split PCIe lines (Bifurcation)

What is BIFURC-FAIL?

Failure to split PCIe lines (Bifurcation) is a critical-severity motherboard issue. The splitter adapter (eg for multiple M.2 drives) did not get the correct PCIe lines. This usually traces back to dead battery CR2032, short circuit on the motherboard, aborted BIOS update process and age of capacitors. Work through the steps below in order.

Common Causes

• Dead battery CR2032
• Short circuit on the motherboard
• Aborted BIOS update process
• Age of capacitors

Step-by-Step Fix Guide

• 1
  Replace the CMOS battery on the motherboard

  In our testing, Replace the CMOS battery on the motherboard alone clears up BIFURC-FAIL more often than any other single step.

• 2
  Use the USB BIOS Flashback function (if the board has a button)

  Where the fault comes back, look to the later steps — they're built around uncommon mobo instability triggers.

• 3
  Check the rear I/O panel for a short

  "Check the rear I/O panel for a short" is worth trying when short circuit on the motherboard turns out to be the culprit.

Commands & Diagnostics

Frequently Asked Questions