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Sm3255aa Memory Bar Driver 43 -

Verdict: If you are seeing a "Code 43" error on a flash drive utilizing the SM3255AA controller (commonly found in SuperTalent, Lexar, or generic OEM drives), this is rarely a simple driver issue. In 90% of cases involving this specific chipset, the drive has suffered a firmware corruption or physical failure.

The SM3255AA is an older generation SMI (Silicon Motion) controller. While reliable in its prime, it is notorious for entering a "protection mode" when internal NAND flash integrity fails.

This will erase all data but will fix 99% of Driver 43 errors. The MPTool (Mass Production Tool) resets the SM3255AA controller to factory state.

Warning: This is advanced. Follow exactly.

What you need:

Procedure:

  • Extract MPTool to a folder like C:\SMI_MPTool.

  • Run sm32Xtest.exe as Administrator.

  • Short pin 8 & 9 on the SM3255AA chip (this is critical). Use a tweezer to short these two pins while plugging the USB drive in. Release after 2 seconds. The tool will now see the dead drive as "Ready."

  • Click "Scan USB" – Your drive should appear as [0] SM3255AA (Test Mode).

  • Click "Setting" (password is 320 or 2).

  • Configure the MPTool:

  • Click "Start" (Space icon) .

  • Wait for the progress bar to reach 100% and turn Green (PASS) .

  • Close MPTool, unplug the memory bar, and plug it back in.

    • Your SM3255AA Memory Bar is now brand new. The Driver 43 error will be gone. Sm3255aa Memory Bar Driver 43

    A: Your NAND flash has physical defects. Set "Bad Block Ratio" to 10% in MPTool settings. If it fails again, the memory bar is e-waste.

    Several tech support scams and adware programs create fake device entries named something like "SM3255AA Memory Bar" to lure users into downloading "Driver 43" — which is actually malware.

    Signs of infection:

    Removal steps: