Bose QuietComfort Headphones F42 Fix (Real-World Guide)

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What This Error Means

Short version: F42 on Bose QuietComfort headphones is a firmware / power fault on the main board.

In the real world, it shows up when the headphones won’t power on properly, won’t charge right, or throw an F42 message in the Bose app or updater while the control board freaks out.

Official Fix

Here’s the clean, by-the-book path Bose support will walk you through.

  • 1. Do a proper Bose reset
    • Turn the headphones off.
    • Wait 30 seconds.
    • Plug them into a USB power source for about 5 seconds.
    • Unplug the USB cable and leave them alone for about 1 minute.
    • Turn them back on and see if F42 is gone and they behave normally.
  • 2. Clear all Bluetooth pairings (rules out pairing corruption)
    • With the headphones on, slide and hold the Bluetooth/power switch to the Bluetooth side for about 10 seconds.
    • Wait for the voice prompt: “Bluetooth device list cleared” (or similar).
    • On your phone/computer, delete the Bose headphones from the Bluetooth list.
    • Re-pair as new and see if F42 or the weird behavior is gone.
  • 3. Force a firmware update
    • Install/open the Bose Music app on your phone or the Bose updater on a computer.
    • Connect the headphones with a USB cable when the app asks for it.
    • If the app or updater sees them and offers an update, run it.
    • Let the update finish. Don’t unplug, don’t turn them off, just let it sit.
    • When done, restart the headphones and check if F42 is gone.
  • 4. Rule out a bad charger or cable
    • Use a different USB cable (good quality, not frayed junk).
    • Use a different USB power source (another wall brick or laptop port).
    • Look into the charging port with a light. If you see lint or crud, gently clean it with a dry wooden toothpick or a soft brush. No liquids.
    • Charge for at least 30–60 minutes, then try powering on again.
  • 5. If F42 stays
    • At this point, the official line is: main board or power section fault.
    • Bose will usually tell you to contact support for an RMA / out-of-warranty swap.
    • On newer models under warranty, they often just replace the headphones instead of repairing the board.

The Technician’s Trick

When the nice reset routine does nothing and F42 keeps coming back, this is the kind of stuff a bench tech will actually try.

  • 1. Deep power drain reset (no tools)
    • Unplug the headphones from any charger.
    • Slide the power/Bluetooth switch to ON and hold it there for a solid 45–60 seconds.
    • You’re forcing the internal regulators and caps to discharge and the microcontroller to fully die instead of half-crashing.
    • Let go, wait 10 seconds, then power on normally.
    • If they suddenly wake up normal, F42 was just a stuck firmware state.
  • 2. Sweat / moisture check
    • If they died after a workout or rain, F42 can be a moisture-triggered fault.
    • Take them off, remove the ear cushions gently, and leave the headphones in a dry, warm room for 24 hours. No hair dryer, no heater blast.
    • After they’re bone dry, try the official reset again, then power on.
  • 3. Battery connector reseat (only if out of warranty and you’re handy)

Warning: You can crack plastic or tear cables. If you’re not comfortable opening electronics, skip this.

  • Pop off the right ear cushion carefully (it’s clipped around the edge).
  • Remove the small screws under the cushion and lift the cover to expose the board and battery.
  • Find the battery connector (small multi-wire plug going into the board).
  • Unplug that connector carefully, wait 1–2 minutes, then plug it back in firmly.
  • Reassemble, then try charging and powering on again.
  • If F42 goes away after this, you had a glitch or slightly loose power connection.
  • 4. Flex test = bad board
    • With the headphones on a charger, gently press or twist around the right earcup.
    • If LEDs flicker, power comes and goes, or F42 appears/disappears with pressure, the board or flex cable is cracked.
    • No magic reset fixes that. You’re looking at a board replacement or new headphones.

Is It Worth Fixing? (The Financial Verdict)

  • ✅ Fix: Still under warranty, or F42 clears after reset/firmware update and maybe a new cable or battery.
  • ⚠️ Debatable: Out of warranty, but you can get a reasonably priced battery or board and you really like these headphones.
  • ❌ Replace: Main board is toast, repair quotes are close to the price of a new pair, or you’ve already chased F42 through multiple “fixes” with no change.

Parts You Might Need

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See also

Dealing with F-codes on other gear too? These guides walk through similar style faults on different devices: