Dover Markem-Imaje 5200, Service Manual

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SECTION 6 Field Replaceable Parts
0855855eng 6/08
6–1
1 Proper Handling of a Circuit Board
Many of the replacement procedures require working with circuit
boards. When handling a circuit board, observe the following:
• Circuit boards are electronically sensitive and can be damaged
by electrostatic discharges (ESD). To prevent damage, use
industry-approved methods and wear a grounded wrist strap.
• Never apply pressure to chips unless installing an EPROM into a
socket.
• If a connector has ejection latches, use them during
disconnection and connection.
• If a screw has a star washer, it must be reinstalled for the system
to properly complete the ground circuit.
• If a circuit board has key holes, make sure to align the screws
with the key holes and fully seat them.
2 Replacing the VPC Module
2.1 What You Will Need
• 3mm metric ball end Allen wrench
• Large flathead screwdriver
• Pliers
2.2 Preparation
1. Power off the Model 5200/5400 and disconnect the power
cable.
2. Remove the front cover by loosening the five large captive
screws.
NOTE: The ground wire may need to be disconnected from the print
station.
2.3 Removal
1. Disconnect the electrical connector (1, Figure 6-1).
2. Disconnect one of the two low vacuum tubes at the clear VPC
plate and the other at the fitting in the enclosure.
3. Disassemble the VPC from the wall by removing the three
screws (2, Figure 6-1, two are shown) using the ball end of the
Allen wrench. Pliers may be helpful to put extra leverage on the
Allen wrench.
4. Disconnect the tubing (3, Figure 6-1) that goes to the enclosure
bulkhead fitting from the tee near the VPC. Cut off and keep
the (clear) urethane tubing with the plastic union from the old
assembly, if the disconnected tube is the thin black type (used
on early model VPCs).