i can't get the 'my brew' settings to save on my precision brewer. i set them, but it just reverts back.

Diagnosis

The Breville Precision Brewer (BDC455BSS) utilizes a small amount of non-volatile memory to store user-defined "My Brew" profiles, but the logic board relies on a constant trickle of power from an internal CMOS backup battery to maintain the registry of these custom settings during power cycles or voltage dips. When this battery—typically a CR2032 coin cell—depletes, the machine loses its ability to "write" and "hold" the specific parameters for bloom time, flow rate, and temperature. You can confirm this is a battery failure if you notice that your clock also resets to 12:00 after a power outage or if the machine behaves as if it has just been taken out of the box after every unplugging. If the settings revert even while the machine is plugged in, it indicates a corrupted memory chip or a failure in the capacitor circuit, but in 90% of cases, it is simply a dead coin cell that can no longer sustain the memory bridge.

How to Fix It

To permanently resolve the memory loss and save your "My Brew" settings, you must replace the internal backup battery. This requires opening the chassis, as the battery is not accessible from the exterior.

1. Unplug the unit from the wall outlet and allow it to cool completely if you have recently brewed coffee.
2. Remove the water tank and the thermal carafe to clear the workspace.
3. Using a Phillips #2 screwdriver, remove the screws securing the outer plastic housing. Be careful not to strip the screws, as the plastic bosses are soft.
4. Carefully lift the outer shell away from the internal frame. Avoid pulling hard, as there are ribbon cables connecting the front control panel to the main logic board.
5. Locate the circular battery holder on the main PCB (printed circuit board). You will see a silver CR2032 coin cell battery.
6. Gently press the small metal retaining clip to pop the old battery out.
7. Insert a fresh CR2032 battery, ensuring the positive (+) side is facing upward.
8. Reassemble the housing and plug the machine back in.
9. Enter the "My Brew" menu, adjust your desired temperature (e.g., 200°F), bloom time (e.g., 30 seconds), and flow rate. Press the "Set" or "Save" button firmly to commit the settings to the now-powered memory.

If That Didn't Work

• Perform a Hard Factory Reset: If the battery is new but settings still won't stick, the NVRAM may be glitched. Unplug the machine for at least 30 minutes. While unplugged, hold the "Brew" button for 10 seconds to discharge any remaining capacitors. Plug it back in and attempt to save the profile again.
• Check for "Demo Mode": Some floor models were shipped in a restricted demo mode that prevents setting saves. Ensure the machine is not in a retail loop by cycling through all brew presets (Gold, Strong, Mild) and then returning to "My Brew" to see if the override triggers.
• Inspect the Control Panel Ribbon Cable: If you opened the machine and the settings still won't save, check the ribbon cable connecting the LCD screen to the board. If the cable is loose or has a pinched wire, the "Save" command from the button may never actually reach the logic board.
• Voltage Stability Check: If you are using a high-surge protector or an extension cord, the machine may be experiencing "brown-outs" that trigger a memory wipe. Plug the BDC455BSS directly into a grounded wall outlet to ensure the logic board is receiving a steady 120V.

Heads Up

• Battery Quality: Use a high-brand name battery (like Panasonic or Energizer). Cheap off-brand CR2032s often have lower voltage thresholds that can cause the memory to fail prematurely.
• Static Warning: When touching the internal PCB, touch a grounded metal object first to discharge static electricity. A static shock to the memory chip can permanently kill the "My Brew" functionality.
• Water Damage: While the battery is replaced, check for any calcium buildup or leaks around the heating element. Scale buildup can cause the machine to overheat, which sometimes triggers a safety reset of the electronic settings.
• Avoid Frequent Unplugging: To prolong the life of the backup battery, avoid unplugging the machine daily. The battery is designed to maintain memory during short outages, not to compensate for constant power cycling.