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Repair and Repl acement Procedures 7-32 ProMa ster 25 00 U ser Ma nual When you have determin ed that the contacts need replacing, perform the operations descri bed in the steps below . You will need the followi ng items…

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Repair and Replacement Procedures
ProMaster 2500 User Manual 7-31
6. Gently feed the new contact set through the underside of the module
into its operating position. The contact set has a notch that fits the
ridge in the module to set the correct alignment. Confirm that these
two are seated before proceeding.
7. Set the retaining bar in position on the contact set, and use the two
screws to hold the bar in place.
8. Insert the contact set on the other side, and tighten its retaining
screws.
9. Reinstall the programming module on the circuit board, observing
the correct orientation as you noted in the first step.
Replacing Contacts
on a PLCC Module
When contacts fail because of a high number of insertions, they generally
exhibit a gradual, progressive increase in programming failures over
several days or weeks. Sudden onset of a high programming failure rate
is usually an indication of some other problem and not a sign of worn
contacts.
One method of keeping track of the number of devices programmed is to
use TaskLink’s Session Data Logging feature (see page 3-19). When
enabled, this option maintains a log of all TaskLink operations and
continuously updates the statistics in a file on your PC. One of the
categories recorded is a count of the number of devices processed during
each Task run. These statistics allow you to calculate the number of
insertions for each device type.
CAUTION: To avoid possible damage to the system components, this
procedure should be performed only by a qualified service
technician.
Figure 7-21
Removing or installing the Contact Set
1929-1
CONTACT SET
RETAINING BLOCK (1 of 2)
SCREW (2 per side)
VIEW FROM BELOW
CROSS SECTION
CROSS SECTION PLANE
TILT CONTACT SET BEFORE
REMOVING OR INSERTING
Repair and Replacement Procedures
7-32 ProMaster 2500 User Manual
When you have determined that the contacts need replacing, perform the
operations described in the steps below. You will need the following
items to complete this procedure:
• 1/16-inch hex driver
• 0.050-inch hex driver
• Four new contact sets
1. Remove the configuration blocks from all four sides (see Figure 7-22).
2. Turn the board upside down. Use the 0.050-inch hex driver to
remove the two screws holding the programming block to the circuit
board. Be careful not to strip the screws.
3. Keep the module in the upside-down position and gently pull the
board from the programming block assembly (see Figure 7-23).
Figure 7-22
Removing the Configuration Blocks
Figure 7-23
Removing the Programming Block
1649-1
CONFIGURATION BLOCK
CONFIGURATION CONNECTOR
CONTACT SET
(1 of 4)
20A
1X
4X
BLOCK ALIGNMENT
PIN (1 of 2)
PROGRAMMING
BLOCK ASSEMBLY
CIRCUIT BOARD
SCREW HOLE (1 of 2)
CONFIGURATION
CONNECTOR (1 of 4)
1669-2
Repair and Replacement Procedures
ProMaster 2500 User Manual 7-33
4. The device ejector pin and ejector spring are loose and will drop out
into your hand when you turn the block upright (see Figure 7-24). Set
these aside; you will reinstall them later.
5. Use a 1/16-inch hex driver to remove the two screws holding the
contact set in place.
6. Gently pivot the base of the contact set out from the programming
block and then lift the set straight up (see Figure 7-25).
7. Wipe the new contacts with a DeoxIT pen from the top of each
contact lead to its end (the portion of the contact that touches the
device’s leads). Remove any excess DeoxIT with a clean, dry cotton
swab. Preparing the leads in this way ensures that they are clean and
well lubricated.
8. Insert the new contact set into the programming block. Hold the set
at an angle and gently feed the tips of the contact set into the holes in
the top of the programming block.
Make certain that all the tips in the set have seated into their holes
before swinging the set’s base into position along the block. Failure to
insert all the tips in their correct positions could result in damage to
the contacts.
Figure 7-24
Removing the Device Ejector Pin
and Spring
Figure 7-25
Removing the Contact Set
1681-2
DEVICE EJECTOR PIN
DEVICE EJECTOR SPRING
PROGRAMMING
BLOCK ASSEMBLY
GOLD PIN
1668-1
CONTACT SET
PROGRAMMING BLOCK
ASSEMBLY
SCREW (1 of 2
per Contact Set)