A bricked MX Keys after firmware update is rare but happens: Logi Options+ update interrupted by app close, USB-C disconnect mid-update, or battery cut. Symptoms: no LED, no response, even plugged in. Good news: Logitech has a recovery mode accessible via key combo + USB-C. Bad news: it's not publicly documented.
Diagnostic
Specific symptoms of firmware brick (vs motherboard failure): (1) it happened immediately after an update; (2) Options+ detects the device as "recovery mode" or "unknown device"; (3) the LED briefly flashes on USB-C plug, then off. If these 3 signs are present, it's recoverable. Otherwise it's probably the motherboard.
Méthode
- 1
Plug the keyboard via USB-C directly to a computer (not through a hub).
- 2
Open Logi Options+ → Help → Reset and reconnect device (recovery option).
- 3
If the keyboard appears as "unknown device", retry the firmware update via Options+.
- 4
If after 3 attempts Options+ cannot recover, contact Logitech support (potential warranty case) or us for workshop JTAG reflash (~€30).
FAQ
How to avoid bricking an MX Keys during firmware update?
Three rules: (1) battery above 50%, (2) USB-C cable plugged and stable during update, (3) don't close Logi Options+ before the "Update complete" message. An update takes 2-3 minutes, be patient.
Can I downgrade an MX Keys firmware?
Officially no — Logi Options+ doesn't allow rollback. But JTAG reflash can write any Logitech-signed firmware. It's complex and needs tools. Our workshop service does it for ~€30.
Why does Logitech still release firmware updates if they brick devices?
Updates fix security bugs (especially Bluetooth) and improve battery efficiency. Brick rate is <0.1% per Logitech. Risk/benefit stays very positive, especially for enterprise keyboards.
Bricked MX Keys = recoverable in 70% of cases via Options+ recovery mode. If unrecoverable, €30 JTAG reflash before throwing away — cheaper than a new motherboard.