Chapter 6 Power Supply And Electrical Parts Adjustment; Precautions At The Time Of Adjustment; Components Inside The Control Box - Brother BAS-311E Service Manual

Chapter 6 Power supply and electrical parts

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.

2. Components inside the control box

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 PCB
The main PCB 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 circuit board
The panel circuit board is fixed to the front panel of the control box. This PCB controls indications of the machine 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
adjustment
Panel circuit board
3.5 FDD
BAS-311E.311EL.326E.326EL

Chapter 6 Power supply and electrical parts adjustment

Control box
Inlee fileer
Main PCB
Conversion transformer
DC fan
Power supply
circuit board
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