Miller Electric MR-5 - Manual (Page 21)

CAUTION: IMPROPER FUSES can damage this
If replacement becomes necessary, use only fuses
of the proper size, type, and rating (see Parts
List).
To replace the fuse, proceed as follows:
1. Depress and rotate fuse holder cover
counterclockwise.
2. Pull out fuse with cover when fuse holder cover
is free.
3. Insert new fuse into fuse holder cover.
4. Install fuse with fuse holder cover back into unit.
5. Depress and rotate fuse holder cover clockwise
until cover is secure.
5
-
3. DISPLAY BOARD METER CHECK (Figure
5-1)
-
Check points are provided on the display board
for checking power supply and input command for the
meters.
~ ELECTRIC SHOCK can kill.
• Do not touch live electrical parts.
• Be sure that personnel performing testing pro-
cedures are familiar with and follow standard safe-
ty practices.
• Shut down unit before making or changing meter
or test equipment lead connections.
ELECTROSTATIC DISCHARGE (ESD) can damage
electronic components.
• Put on a properly grounded wrist strap BEFORE
handling circuit boards.
• Transport all static-sensitive components in pro-
per static-shielding carriers and packages.
• Perform work only at a static-safe work area.
unit.
3. Check voltage according to Figure 5-1.
4. If a meter power supply and command voltage is
correct and the meter is not working, replace the
meter (see Section 5-4).
5. If the power supply or command voltage is incor-
rect, replace display board PC4 (see Section
5-4).
5
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4. BOARD REPLACEMENT PROCEDURES
(Figure 5-2)
ELECTRIC SHOCK can kill.
• Do not touch live electrical parts.
• Shut down unit, welding power source, and
robot, and disconnect input power employing
“lockout/tagging procedures” before inspecting
or servicing.
Lockout/tagging procedures consist of padlocking line
disconnect switch in the open position, removing fuses
from fuse box, or shutting off and red-tagging circuit
breaker or other disconnecting device.
ELECTROSTATIC DISCHARGE (ESD) can damage
circuit board components.
• Put on properly grounded wrist strap BEFORE
handling circuit boards.
• Transport all static-sensitive components in pro-
per static-shielding carriers or packages.
• Perform work only at a static-safe work area.
INCORRECTLY INSTALLED PLUGS can damage
circuit boards.
• Be sure that plugs are properly aligned and install-
ed onto connectors before resuming operation.
All directions, such as left or right, are
with respect to the operator facing the unit front panel.
Retain all hardware removed during this procedure for
reinstallation.
A. Display Board PC4 And Meter Replacement
WARNING:
IMPORTANT:
1. Remove computer interface top cover.
1. Remove unit top cover.
2. Locate display board PC4.
Figure 5
-
1. Display Board Meter Checks
OM-882 PageS