FAQ - K40

About Connection & Pairing

How do I re-pair the 2.4G USB receiver?

Please follow the steps below to re-pair your keyboard with the 2.4G receiver:

Insert the USB receiver into your computer’s USB port.
Turn on the keyboard and briefly press the 2.4G channel button to switch to 2.4G mode.
Press and hold the 2.4G channel button until the indicator light starts flashing rapidly (pairing mode).
Quickly unplug and reconnect the USB receiver.
Keep the keyboard as close as possible to the receiver during this process.

Completed: The keyboard and receiver will automatically complete the pairing process.

How do I reset and reconnect Bluetooth?

Please follow the steps below:

Enter Bluetooth pairing mode:

Turn off the keyboard.
Press and hold ESC + 3 (please use the number 3 in the main keyboard area, not the numeric keypad).
While holding the keys, turn on the keyboard.
When the channel indicator flashes rapidly and then remains solid, release the keys.

Connect your device:

Open your device’s Bluetooth settings.
Search for and select the keyboard name to connect.

Tip: If your device cannot find the keyboard, please try turning Bluetooth off and back on again.

Do I need to pair Bluetooth again every time I turn on the keyboard?

No.

The keyboard has a memory function and will automatically reconnect to the last connected channel after powering on. The corresponding channel indicator will light up when connected.

Why is the keyboard not responding or unable to type?

Please check the following:

Make sure the keyboard is switched to the correct connection mode.
If the current channel is not connected, press the corresponding channel button and wait about 4 seconds before using the keyboard again.

About Common Troubleshooting

What should I do if the keyboard does not work, cannot connect, disconnects frequently, repeats characters, has typing delays, or inputs multiple characters?

Please try the following solutions:

Check your device power:

If your connected device (PC, phone, tablet, etc.) has less than 20% battery, please charge your device first.
A low device battery level may affect the keyboard connection and performance.

Check the keyboard battery:

Please make sure the keyboard has enough power before use.
We recommend charging the keyboard through a computer USB port.
A flashing power indicator means the keyboard battery is low.

If using the 2.4G USB receiver:

Remove and reconnect the USB receiver.
Try another USB port.
Make sure the keyboard is switched to 2.4G mode.

If using Bluetooth:

Turn Bluetooth off and back on from your device settings, then press any key on the keyboard to reconnect.
Remove the keyboard from your device’s Bluetooth paired list.
Restart your device and pair the keyboard again.

If the issue continues or you need further assistance, please contact ProtoArc Customer Support.

What should I do if the keyboard/mouse cannot turn on or suddenly stops working?

1. Charge correctly

The recommended charging voltage is 5V.
We recommend charging through your computer’s USB port.

2. Check the charging cable

Try using another Type-C charging cable to confirm whether the issue is caused by the cable or the device itself.

3. Contact customer support

If the power indicator does not light up at all while charging, please contact our support team for further assistance.

Charging & Battery Life

What happens when the keyboard battery is low?

When the battery is low:

The red low-battery indicator will continue flashing until the keyboard powers off automatically.
You may experience connection delays or typing interruptions.
Please charge the keyboard as soon as possible.

How do I charge the keyboard?

Connect the Type-C cable to the keyboard.
Connect the USB-A end to your computer’s USB port.

During charging:

The indicator light will remain red.

How long does it take to fully charge? How can I tell when charging is complete?

Full charging time: Approximately 2–3 hours.

Charging indicator:

Red light: Charging
Green light: Fully charged

Sleep Mode & Wake-up

Why does the keyboard stop responding after being idle for a while?

This is a normal power-saving feature.

When the keyboard has no activity for approximately 60 minutes, it will automatically enter sleep mode to save battery.

How do I wake up the keyboard from sleep mode?

Simply press any key on the keyboard.
The keyboard will wake up and automatically reconnect.

About Keys & Function Settings

Why do F1–F12 keys activate multimedia functions instead of standard F keys?

This happens because the FN Lock function is turned off by default.

In this mode:

Pressing F1–F12 directly activates multimedia functions.
Pressing FN + F1–F12 activates standard F-key functions.

How do I switch between multimedia functions and standard F1–F12 functions?

Press FN + ESC to switch modes.

FN Lock OFF (Default):

Press F1–F12 → Multimedia functions
Press FN + F1–F12 → Standard F1–F12 functions

FN Lock ON:

Press F1–F12 → Standard F1–F12 functions
Press FN + F1–F12 → Multimedia functions

Why are the keys incorrect when using the UK QWERTY layout?

Please make sure your device keyboard language is set to English (UK) before use.

Samsung Tablet:

Go to: Settings > General Management > Samsung Keyboard Settings > Languages and Types > Manage Input Languages > Select English (UK).

OPPO Phone:

Go to: Settings > Additional Settings > Languages & Input > Physical Keyboard > ProtoArc K40 > Set Keyboard Layout > Select English (UK).