The Logitech K750 Mac is designed to run from light, but its internal rechargeable battery can lose capacity with age. When that happens, the keyboard may work only briefly, stop working in low light, or become unreliable even after sitting under bright light. Replacing the battery can extend the life of the keyboard, provided the rest of the electronics and the solar panel are still functioning.
Before replacing the battery
Battery failure is not the only possible cause of power or connection problems. Before opening the keyboard, clean the solar panel and leave the keyboard in bright light for an extended period. Also check the wireless receiver, confirm that the keyboard is switched on, and make sure the problem is not limited to pairing or connectivity.
A replacement is more worthwhile when the keyboard is in good physical condition and the keys, solar panel, and wireless connection work normally apart from the battery issue. If the keyboard has several unrelated faults, a replacement keyboard may be more practical.
What you will need
- A compatible rechargeable battery pack intended for the Logitech K750 Mac
- A small Phillips screwdriver
- A plastic spudger or another non-marring pry tool
- A magnifying glass or suitable task lighting
- A low-wattage soldering iron, if the battery is soldered to the circuit board
Do not select a battery based only on its physical size. The replacement must match the keyboard’s electrical requirements, connector, and polarity. A pre-wired pack made specifically for the K750 Mac is generally easier to install than a bare cell. If the battery is soldered in place and you are not experienced with small electronics, using a repair technician is the safer option.
Safety precautions
Remove the USB receiver and switch off the keyboard before beginning. Work on a clean, static-free surface and keep track of every screw. Do not puncture, crush, or overheat the rechargeable battery. Pay close attention to the positive and negative connections, and do not force a plug into the wrong orientation.
Opening the keyboard may affect any remaining warranty. If the device is still covered, check the available support options before starting. Set aside a damaged or removed battery for appropriate recycling or disposal rather than placing it with ordinary household waste.
Battery replacement procedure
- Remove the back screws. Turn the keyboard over and remove the visible screws. Some may be concealed beneath rubber feet or labels, so inspect the back carefully and lift coverings gently.
- Separate the case. Use a plastic spudger to release the clips around the edge of the housing. Work slowly and avoid using excessive force, especially near the solar panel and thin plastic sections.
- Locate the battery. Inside, identify the rechargeable battery pack and note how it is secured. Take a photograph before disconnecting anything so the original routing, polarity, and position are clear during reassembly.
- Disconnect or desolder the old pack. If there is a plug, pull the connector out by its body rather than tugging on the wires. If the leads are soldered, remove them carefully from the same points where the replacement will be attached. Avoid prolonged heat on the circuit board.
- Install the replacement. Connect or solder the new pack with the same polarity and orientation as the original. Insulate the connections and secure the battery in its original location so it cannot move inside the case.
- Test before closing the case. Reconnect the receiver, switch on the keyboard, and place it under bright light. Check that it connects and that the keys respond. If the test is successful, refit the case and reinstall the screws without overtightening them.
Troubleshooting after installation
If the keyboard remains intermittent, first check that the battery connector is fully seated or that the solder joints are secure and free from accidental bridges. Confirm the receiver connection and pairing as well. A keyboard that powers on but does not accept keystrokes may have a loose ribbon cable between the key matrix and the circuit board.
Allow the replacement battery time under bright light before judging its performance. If the keyboard still fails after the connections have been checked, the fault may involve the solar panel, circuit board, or another internal component rather than the battery.
Repair or replace?
A battery replacement makes sense when the keyboard is otherwise comfortable and reliable, and when the required part and repair effort are reasonably available. Professional repair is a good alternative if the pack is soldered or the case is difficult to open. If the keyboard is heavily worn or additional electronics have failed, replacing the entire keyboard may cost less effort than continuing the repair.
After the repair, keep the solar panel clean and give the keyboard regular access to indirect daylight. Avoid storing it for long periods in darkness, since the internal battery depends on the solar panel to maintain its charge.
