Sachs Bikes MadAss 125 Owner's Manual page 60

NOTES ON MAINTENANCE
Tail / brake light
1
The tail / brake light (1) is not fitted with a
replaceable light bulb (diode light).
If the tail light does not work you should
first check, whether a cable connection is
interrupted.
56
If this is not the case, the tail light must be
replaced by a Sachs dealer.