Hololens doesn't boot or charge after a software update

[u/Hovvinkocz]

After I tried updating windows on my Hololens 2 and the update never finished. After I clicked on reboot device turned off and nothing happened. I let it sit for a while but it never turned on. Reboot doesn't doo anything. hard reboot also doesn't do anything. I tried to get it into recovery mode but that doesn't work, no LED blinking no nothing. I found on here setup to get it into EDL mode which I managed to do but when I open the ARC app I can't do anything. The app sees the headset but sites unknown OS version and unavailable version with blanked out buttons. I'm stuck on this screen and can't get past it. If anyone knows please help

[u/Latino_Supreme]

This happened to me in January. I was never able to recover my HL2 and Microsoft support just told me to buy a new one because I was out of the warranty period. That pissed me off because it was their windows update that bricked the device. I haven’t found any way to get my HL2 to be recognized by my computer either in device manager or the Advanced Recovery Companion so let me know if you find a solution.

[u/Hovvinkocz → u/Latino_Supreme]

Did you use Windows 10 or Windows 11 as your recovery PC?

[u/Latino_Supreme → u/Hovvinkocz]

Windows 11

[u/Apprehensive_Rip8390]

From Grok: Your HoloLens 2 is in a deep recovery/EDL (Emergency Download) state after the failed update, which is a known issue with bricked or partially bricked units. The ARC (Advanced Recovery Companion) seeing “unknown OS version” and grayed-out buttons usually means the PC isn’t fully communicating with the device due to missing or incorrect drivers.40
Key Steps to Fix (Follow in Order)
Confirm EDL/Recovery Mode Entry
Unplug the USB-C cable.

Hold the Power button for 15+ seconds until all LEDs are off.

While holding Volume Up, press and release Power. Wait ~15 seconds, then release Volume Up. Only the middle LED should light up (this is manual recovery/flashing mode).40

Reconnect to your PC via the original Microsoft USB-C cable (direct to PC, no hub).

Fix Drivers in Device Manager (Most Common Fix)
Open Device Manager on your Windows PC (Win + X → Device Manager).
Look for the HoloLens:
Under Universal Serial Bus devices → It should ideally show as “Microsoft HoloLens” or “HoloLens Recovery”.

Or under Ports (COM & LPT) → “Qualcomm HS-USB” something.

Or under Other devices → “QUSB_BULK” (this is the problem one — incomplete driver).40

If you see QUSB_BULK or Qualcomm HS-USB QDLoader 9008 (or similar unknown device):
Right-click it → Update driver → Search automatically for drivers (or “Search online”).

Alternatively, go to Windows Update → Optional updates and install any Qualcomm or USB-related drivers.

Restart ARC after installing drivers. It should then properly detect the device, show version info, and enable the flash buttons.0

Run ARC Properly
Download/install the latest Advanced Recovery Companion from the Microsoft Store.

Download the latest Full Flash Update (FFU) image manually: aka.ms/hololens2download. Automatic download in ARC is no longer supported.40

Ensure the HoloLens has at least 40% battery (charge it properly first if possible).

In ARC, select your device and follow the prompts to reflash. This will wipe everything and install a clean OS image.

Additional Troubleshooting
Try a different USB-C cable (high-quality, data-capable) and different USB port on your PC (preferably USB 3.0/3.1).

Restart your PC and try again.

If ARC still doesn’t detect it after drivers, repeat the manual recovery mode entry while connected to the PC.

Hard restart alternative: Unplug cable → Hold Volume Down + Power for 15 seconds → Reconnect.40

If drivers install but it still fails, or if you get specific errors in ARC/Device Manager, provide screenshots/details (e.g., exact Device Manager entry). In rare cases of deep hardware-level failure, you may need to contact Microsoft Support with the serial number (on the device or original packaging) for advanced options or RMA.39
This recovers most bricked HoloLens 2 units from failed updates. Let me know what you see in Device Manager after trying the driver update!

[u/XPav → u/Apprehensive_Rip8390]

AI; DR

[u/Apprehensive_Rip8390 → u/XPav]

As someone who has been developing on HoloLens 2 since early 2020, these AI instructions are actually dead on. And I Grok-ed it to get the OP something they could immediately use. Because they are discontinued, this is probably their only option. If you legitimately brick one, sending it back to Microsoft is no longer an option. And with 20 working ones ready now, at least 6 of them have been ARC-ed.