Circuit Board - Husqvarna DM 230 Workshop Manual

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C D
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A

CIRCUIT BOARD

Circuit board
The circuit board at the rear of the motor controls the motor's functions.
Ensure the cable runs and connections are correct when reassembling:
1. Green cable – connects to earth point in the handle.
2. Grey cable – connects to stator winding.
3. Grey cable – connects to stator winding.
4. White cable – connects to switch in handle, point D below.
5. Black cable – connects to switch in handle, point C below.
6. Black cable – connects to Smartstart switch, position 9, page 4.
7. Red cable – connects to Smartstart switch, position 9, page 4.
Dismantling
Loosen the cable connections
1–7.
Remove the screw, marked with
an arrow.
Functional test
Measurement to identify whether the circuit board is intact requires specialist
knowledge and test equipment. The process of elimination is used rather than
troubleshooting. If the rotor and stator have been found to be in working
order, you can assume that the circuit board is defective.
Smartstart™
The switch completes the circuit each time the Smartstart button is pressed.
The impulse is transferred on to the circuit board which switches the motor
between full and half power.
Functional test
Ohm measurement is an easy way of checking that the switch short circuits
when the Smartstart button is pressed. The machine does not need to be dis-
mantled to run this check. Only remove the inspection cover and measure bet-
ween 6 and 7, as per the illustration at the top, without disconnecting the cables.
For replacement of components in the handle, start by dismantling the
handle from the motor body. Insert a long screwdriver and loosen both
screws. Now dismantle the handle.
Switch/mains cable
Remove the screw that joins the two handle halves.
Note the connections if the switch or mains cable must be replaced:
A: Mains supply
B: Protective earth yellow/green cable. An additional cable (green) is
connected here
C: Black cable
D: White cable
Dismantling
Lift off the cable connections 1–5 and
unscrew the cables 6 and 7 with a small
screwdriver.
Remove the screw marked with an arrow.
You can now remove the circuit board.
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