Replacing the CMOS battery on the BeoLink 7000

An essential part of the restoration process for the BeoLink 7000 is replacing the CMOS battery. The CMOS battery ensures that the processor preserves its configuration, should the main battery run out of power. The estimated lifetime of a coin cell battery is up to 8 years. Since the BeoLink 7000 is from the 1990s, it is well past its expected lifetime.

Replacing the battery is straightforward, but you need to remove the display and keypad as described in one of my previous posts. 


To release the main PCB, you must remove the ribbon cable and the two screws. 


Unsolder the old battery and clean the vias. Solder the new battery in place. The positive cathode (+) is the one facing away from the centre of the PCB.



I usually add a piece of tape to the upwards-facing side of the PCB to protect it from short circuits.

Remember to clean the ground connector and replace the 4.7uF capacitor. 


Assembled again and ready for testing.


Under no circumstances should you solder a lithium coin cell battery. It can and will explode if you are inexperienced. Instead, you can buy batteries with solder pins attached. I usually buy mine from AV Classics in Austria.