Electric Mechanism; Precautions At The Time Of Adjustment; Components Inside The Control Box And The Operation Panel - Brother LK3-B430E Mark II Service Manual

10. ELECTRIC MECHANISM

10. ELECTRIC MECHANISM

10-1. Precautions at the time of adjustment

Pay attention to the following when opening the control box for maintenance.
Electric shock
Some large capacitors may have a high voltage remaining in them for up to 5 minutes after the power is
turned off. To prevent electric shock, wait at least 5 minutes after the power is turned off before doing the
following:
¡ Opening and closing the control box
¡ Replacing fuses
¡ Separating and joining connectors
¡ Measuring resistance
¡ Doing anything with a possibility of touching something inside the control box
Some adjustments require measuring the voltage while the power is turned on with the control box kept
open.
In such a case, be careful not to touch any place other than that for the measurement. In addition, always
keep in mind that a high voltage remains for 5 minutes after the power is turned off.
Injury
While the power is turned on, the cooling fan of the control box operates; be careful not to get caught in it.
When separating or rejoining connectors, and measuring something, be careful not to cut your fingers on
metal parts such as heatsinks and covers.

10-2. Components inside the control box and the operation panel

The following are brief explanations of components inside the control box. See control circuit block diagram
at the end of this manual for the details of the connections.
Main circuit board
The main circuit board is fixed to the rear panel of the control box. This PCB serves to control machine
operation.
Power supply circuit board
The power supply circuit board is fixed at the bottom of the control box. Four fuses are mounted on this
PCB.
Panel PCB
The panel PCB is fixed to the front panel of the operation panel. This PCB controls indications of the ma-
chine status and the input operation.
DC fan motor
The DC fan motor serves as a fan to cool the inside of the control box. Clean the inlet filter monthly.
Conversion transformer (depending on power supply voltage specification)
The conversion transformer controls the power supply voltage to provide 220 V.
Operation panel
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Panel PCB
Main circuit board
LK3-B430E Mark II
Air inlet
Control box
DC fan motor
Power supply
circuit board