my echo show 15 just sits on the 'hello' screen and never actually boots up, i've left it for 30 minutes.

Diagnosis

This issue, commonly referred to as a "boot loop" or "soft-brick," occurs when the Echo Show 15's Fire OS fails to initialize the user interface layer after the initial kernel load. When the device hangs on the 'Hello' screen, it means the hardware has powered on and the bootloader has functioned, but the system is unable to authenticate the device with Amazon's servers or load the local user profile due to a corrupted cache partition or a fragmented firmware update. This typically happens if the device lost power during a background OTA (Over-the-Air) update or if there is a synchronization conflict between the device's unique hardware ID and the cloud-based account registration. You can confirm this is a software hang rather than a hardware failure if the screen is bright and the 'Hello' text is crisp; if the screen were flickering or showing vertical lines, it would indicate a failure of the internal display ribbon cable or the main logic board.

How to Fix It

To resolve a boot hang on the Echo Show 15, you must force the device to clear its temporary cache and re-initialize the setup wizard through a hard hardware reset. Follow these exact steps:

1. Disconnect the power adapter from the wall outlet entirely. Do not just turn off the power strip; physically remove the plug to ensure all capacitors on the motherboard are drained.
2. Wait exactly 60 seconds. This ensures the volatile memory (RAM) is completely cleared.
3. Locate the physical buttons on the top edge of the device. Identify the Action button (the button with the dot/circle icon).
4. Press and hold the Action button firmly. While continuing to hold the button, plug the power adapter back into the wall outlet.
5. Continue holding the Action button for a full 15 to 20 seconds. You will see the 'Hello' screen again, but do not let go until the Amazon "smile" logo appears on the center of the screen.
6. Once the logo appears, release the button. The device will now perform a factory reset and rebuild the system partition.
7. Wait for the device to reach the "Welcome" screen. You will now need to re-link the device to your Amazon account using the Alexa app on your smartphone.

If That Didn't Work

• Power Cycle the Network Gateway: Sometimes the Echo Show 15 hangs on the 'Hello' screen because it cannot establish a handshake with your DNS server to verify the account. Unplug your router and modem for 30 seconds, reboot them, and then attempt the boot process on the Echo Show again. If the device can't "call home," it may stall the boot sequence indefinitely.
• Swap the Power Adapter: The Echo Show 15 requires a specific voltage and amperage to boot the high-resolution panel and the processor simultaneously. If the power brick is failing and providing insufficient current (under-volting), the device may have enough power to show the splash screen but not enough to launch the OS. Try using a known-working power adapter from another Echo Show 15 to rule out a faulty AC adapter.
• Check for Physical Button Jam: Ensure that the volume buttons or the mute switch on the top edge are not stuck in a depressed position. If a button is held down during the boot sequence, the device may enter a recovery mode or a diagnostic loop that prevents the 'Hello' screen from progressing to the setup menu.
• Perform a Hard Power Drain: Unplug the device and hold the Action button for 30 seconds while it is unplugged. This discharges any remaining electricity in the internal circuitry. Plug it back in and see if it boots normally without the reset sequence.

Heads Up

• Avoid Power Interruption: Never unplug the device while the screen indicates an update is in progress; this is the primary cause of 'Hello' screen hangs.
• Wall Mount Clearance: If you have the device wall-mounted, ensure the back of the unit has at least a small gap for ventilation. Overheating during a heavy update can cause the system to crash and corrupt the boot files.
• Firmware Stability: Once you get the device booting again, immediately go to Settings > Device Options > Check for Software Updates to ensure you are on the latest stable build to prevent a recurrence.
• Account Sync: If the problem persists across multiple resets, log into your Amazon account on a web browser, go to "Manage Your Content and Devices," and remove the Echo Show 15 from your registered devices before attempting the setup again.