The Logitech K750 is one of the most popular wireless solar keyboards ever made. It’s thin, lightweight, charges itself with indoor light, and is generally bulletproof. But there’s one problem thousands of users run into:
The tiny USB receiver gets lost.
A misplaced receiver can make the entire keyboard seem unusable, and Logitech doesn’t make it obvious which replacement you need or how to reconnect your keyboard once you have one.
This guide walks you through exactly what to do when your Logitech K750 solar keyboard receiver is lost, including compatibility, pairing steps, alternatives, and permanent solutions.
Table of Contents
🔍 Step 1: Identify Which Receiver the K750 Uses
The Logitech K750 only works with the Logitech Unifying Receiver — the one with the orange star logo.
It does NOT work with:
- Logitech Bolt receivers
- Generic 2.4 GHz dongles
- Logitech Nano receivers from non-Unifying mice
- Bluetooth (the K750 does not support Bluetooth)
So if your original receiver is lost, you must get a Logitech Unifying Receiver, model number C-U0007, C-U0010, or C-U0018. All of these are compatible.
🛒 Step 2: Buy a Replacement Unifying Receiver
Here are the official replacement options people typically use:
✔️ Logitech Unifying Receiver (Recommended)
- Works with the K750 and up to 5 other Logitech devices
- Uses the standard Unifying pairing software
- Most reliable long-term solution
✔️ Unifying Receiver + Spare (Best practice)
Many users buy a two-pack, because these tiny receivers disappear frequently.
✔️ Avoid cheap no-name clones
They often:
- Fail pairing
- Disconnect randomly
- Break after weeks
- Don’t support firmware updates
Stick with Logitech-branded receivers.
🔧 Step 3: Download the Logitech Unifying Software
Once you have the receiver, pairing the K750 requires a specific tool.
Download: Logitech Unifying Software (Windows/macOS)
https://support.logi.com
This software lets you:
- Add a device
- Remove old devices
- Repair devices
- Update receiver firmware
The Unifying tool is simpler and more reliable than Logi Options+ for initial pairing.
⌨️ Step 4: Put the K750 Into Pairing Mode
The K750 does not have a special pairing button. Instead, pairing happens automatically:
- Turn off the keyboard
- Open the Logitech Unifying Software
- Click Add a Device
- Turn the keyboard on when prompted
- Wait for detection
- Type the test code to confirm pairing
If pairing fails, retry with the keyboard closer to the receiver.
⚠️ If the Keyboard Won’t Pair
Try these troubleshooting steps.
1. Charge the keyboard fully
Place it under bright indoor light or direct sunlight for 1–2 hours.
Low battery = failed pairing attempts.
2. Remove old paired devices
In the Unifying Software:
- Remove unused entries
- Add the keyboard again
3. Use a USB 2.0 port
Avoid USB 3.0 ports (blue), which create 2.4 GHz interference.
4. Use a USB extension cable
Place the receiver:
- On your desk
- Within 12–18 inches of the keyboard
- Away from metal surfaces
5. Soft reset the keyboard
- Turn the keyboard off
- Hold Esc
- Turn the keyboard on while holding Esc
- Release after 5 seconds
Then try pairing again.
🔁 Step 5: Consider a Single-Receiver Setup
If you own other Logitech wireless devices, you can pair them all to one Unifying Receiver:
- MX Master mice
- M510, M705 mice
- K360, K520, K800 keyboards
- Many older Logitech devices
You can connect up to six devices to one receiver.
🔋 Step 6: Replace the K750 Battery (Often Overlooked)
Even though the K750 is “solar,” it uses a CR2032 coin-cell battery.
A failing battery can cause:
- Random disconnects
- Failed pairing
- Keyboard only working under bright light
Replace the CR2032:
- Flip the keyboard
- Slide out the battery tray
- Insert a new coin cell
- Charge in bright light for 1–2 hours
- Retry pairing
The solar panel only charges the battery; it does not directly power the keyboard.
🧠 Alternative: Bolt Receiver (Only for Newer Keyboards)
Important: The K750 does NOT support Bolt receivers.
However, if you ever upgrade to newer Logitech keyboards (MX Mechanical, MX Keys for Business, etc.), Bolt offers:
- Better security
- Stronger wireless reliability
- Bluetooth fallback
But again, not compatible with the K750.
🧰 Final Troubleshooting Checklist
If the K750 still won’t connect, check:
- Is the receiver a genuine Logitech Unifying Receiver?
- Is the keyboard fully charged?
- Is the CR2032 battery new?
- Is the receiver in a USB 2.0 port?
- Have old paired devices been removed?
- Are you using the official Logitech Unifying Software?
- Is USB power-saving disabled on your PC?
Most failures come from:
- Wrong receiver type
- Weak batteries
- USB 3.0 interference
- Old pairing data
🎉 The Bottom Line
If you lost the receiver for your Logitech K750 solar keyboard, the fix is straightforward:
- Get a Logitech Unifying Receiver (orange star)
- Charge the keyboard well
- Pair using the Unifying Software
- Use a USB 2.0 port or extension cable
- Replace the CR2032 battery if needed
Once paired, the K750 works like new and can last for over a decade with proper care.
🏷️ Logitech Keyboard Deals ⭐⭐⭐⭐⭐