An MX Keys that won't charge is usually one of three issues: the USB-C cable is faulty, the keyboard's USB-C port is damaged, or the lithium-polymer battery has reached end of life. On a keyboard several years old, the battery is the most likely suspect; on a recent one, it is more often the cable or the port. Diagnosis takes 5 minutes with another quality USB-C cable.
Diagnosis
Test in this order: (1) swap to another USB-C cable — use a data + charge cable, not charge-only; (2) try another USB-C port (on a computer, certified wall charger); (3) if the LED still doesn't light when plugged in, leave the keyboard out of cold storage or pause it for 24h; (4) if after these tests the charge LED still doesn't blink, the battery is most likely failing.
How to fix it
- 1
Try another quality USB-C cable (data + charge), and switch USB ports too.
- 2
Plug it in for a full hour without using the keyboard — a deeply discharged battery needs time to start charging.
- 3
If the charge LED stays off despite valid cables and ports, the battery or internal port is the cause.
- 4
Order an MX Keys battery (€9.99) or contact us for workshop diagnosis if you don't want to disassemble.
FAQ
How long does an MX Keys battery last?
Logitech rates up to 10 days with the backlight on and up to 5 months with it off. Over the years the battery loses capacity, at a pace that depends on use and on the number of charges.
Is the USB-C port of my MX Keys replaceable?
Yes, but it's complex: the USB-C port is soldered on the motherboard. Replacement requires desoldering. The simplest fix: replace the whole motherboard (€14.99). If you don't want to disassemble, contact us for a workshop return.
How much does an MX Keys battery cost?
€9.99 each from our catalogue. The standard MX Keys and the MX Keys Mini each have their own battery, at the same price: pick the one for your model.
An MX Keys that won't charge is rarely beyond saving. Test cable and port first, then a €9.99 battery if needed; at worst, a €14.99 motherboard.