Tweco 300 S Arcmaster - Manual (Page 44)

ARCMASTER ® 300 S
March 31, 2006 11-2
11.03 Switching VRD On/Off
Switch the machine Off.
a) Remove the clear plastic cover from the control panel (see Figure 11).
• Lift up the cover so it rests on the top of the unit.
• Place a small fl at bladed screw driver between the cover hinge on the front panel.
• Gently lift the cover hinge out of the front cover mounting hole.
• Remove the control’s clear plastic cover.
b) Remove four mounting screws from the control panel (see Figure 12).
c) Access the VRD control by gently prying back the front panel controls to reveal the VRD on/off potentiometer (see Figure 12).
d) Turning the VRD ON/OFF (see Figure 13).
• To turn VRD ON: rote the trim potentiometer (VR1) on the display PCB fully clockwise. When VRD is turned ON check that
it operates as per VRD Specifi cations on page 5-13.
• To turn VRD OFF: rote the trim potentiometer (VR1) on the display PCB fully counter clockwise.
Figure 11 - VRD ON/OFF Step A
CAUTION
Do not pull back the front panel with excessive force as this will unplug control PCB. Plugging the control PCB back
into the front panel controls can only be achieved by removing the side covers.