Vr1 & Vr2 Setting Of Treadle Unit - Brother MD-602 Service Manual

14. VR1 & VR2 setting of treadle unit
PS-INV Assy (MD-602, 612)
After changing this circuit board. Please adjust the volume (VR1, VR2) since we suppose that the voltage of each position
may change due to the aberration of position of magnet and hole element when you set this circuit board onto the treadle
base.
Points of adjustment;
Please adjust the position of P2 with VR1 and the position of P6 with VR2.
• Adjustment of the position of P2 means that the pedal-lever should be the neutral position.
• Adjustment of the position of P6 means that the pedal-lever should be the position of full with forward stepping opera-
tion.
PEDAL-LEVER NEUTRAL (P2)
PEDAL-LEVER FULL (P6)
There are two adjusting ways as follows.
1. Please indicate the voltage after indicating (A3) in 7-segment display in (CP) check mode.
(1) [ ] + [ ]
(2) [ ] + [ ]
(3) [ ] of B
(4) [ ]
(5) [ ]
Then please adjust to display 14 – 16 in the neutral position, if you turn VR1 in clock-wise the value goes down.
Please adjust VR2 to display 45 – 47 in the full step position of pedal, if you turn VR2 in clock-wise the value goes up.
Please adjust VR1, VR2 repeadly to locate the value within the above each limit.
2. Please measure the DC-voltage with the tester to put + pole to connecter No.2 and – pole to connecter No.3 and then
adjust VR1 and VR2 to locate the volume within the above each limit.
34
DC-voltage
DC1.4 – 1.6V
DC4.5 – 4.7V
[ d S ]
[ S P ]
[ C P ] Input/output check mode
[ A 3
] HEXA
[ A 3 ] DECMAL
DISPLAY OF OPERATION PANEL
14 – 16
45 – 47
MD-602, 612
TYPICAL
1.5V
4.6V