F 504
T6.3A
F 505
T6.3A
F 506
T6.3A
F 507 
T6.3A
Diagram 10 printed circuit board 85264.2 with inserted DC fuses F502 and F507
Changing the fuses F502 and F503:
The battery fuses F 502 and F503 are located on the printed circuit board 85264.2, behind the AMP battery connections. In case they need to be exchanged, the top cover plate (see also paragraph 8) and the rear cover plate of the appliance have to be detached. Unlock the screws marked as “A”see( also the diagram on page 2, picturing the rear cover plate). The 4-pole flat cable between the two relays that is connected to the male multi-point connector B502 on the printed circuit board has to be disconnected. Now, the hinged rear plate can be turned up and taken out. Be careful not to damage any printed circuit board or the wiring. The fuses F502 and F503 are now easy to get to (see also diagram 10). Follow the same procedure in the opposite order to reattach the rear cover plate. After tightening the screws of the rear plate, the 4-pole flat cable has to be reconnected to the male multi-point connector B502. The top cover plate has to be reattached.