LS SERIES SERVICE MANUAL
ISSUE 4.0 FAULT FINDING 1
10. FAULT FINDING
10.1 General
Before starting any detailed fault finding, always check the power supplies.
Also note that the PCBs are multi-layered and are fitted with surface mounted components
so are NOT
considered to be field repairable. If a PCB fails, the usual course of action is to
replace it with a new one. Therefore it is recommended to keep spare PCBs in your service
stock.
The Motor Drive PCB may have limited repair work carried out on it, mainly replacing the
PWM Driver IC and the voltage regulators.
10.2 Mains Supply Checks
Troubleshooting techniques should always include fuse checks, voltage measurements and a
visual inspection for loose or broken connectors.
The input power connector contains 2 fuses, one in each line, and these should be checked if the
machine shows no sign of power.
To check these fuses, remove the mains connector from the socket on the rear of the machine then
unclip the top of the socket using a thin bladed screwdriver. The 2 fuses can then be pulled out
together with their holders.
Note that the fuseholder is designed to use either 20mm fuses or 1-1/4 inch fuses but 20mm
fuses MUST always be used. Also note the fuse locations within the fuseholder.
Always replace any fuse with the same type and size as the original. Refer to the Serial
Number Label for the relevant fuse details.
Note that the fuses MUST be
fitted with one end against
the pin end of the holder
To Next Page
Loading...
