Micromod Micro-DCI: 53ML5100A LOADING STATION - Manual (Page 48)

Replacing the display unit requires reconnecting the display end of the cable to the new front dis-
play panel, inserting the extended portion of the display panel into the instrument cabinet and latch-
ing it in place with a screwdriver.
After the front display panel is removed, the main printed circuit board can be accessed. The
main printed circuit board also has the power supply as well as the microprocessor circuitry. To re-
move the main PCB, use its front edge board ejector to pull it free from the rear terminal board
slot and carefully slide it from the case. Disconnect the front display panel flat ribbon cable from
the main PCB. The replacement main PCB can now be installed. Connect the front display
panel ribbon cable and slide the PCB into the instrument case. Seat it into the rear terminal board
slot and install the front display panel.
The power supply can be accessed when the main PCB is removed. The power supply is
mounted on three standoffs to the main PCB. Also, there are three sockets that connect the power
supply outputs to the main PCB. Each socket connector occupies a separate side of the power
supply board. To remove the power supply from the main PCB, remove the three retaining
screws from the standoffs and carefully pull the power supply straight up to disconnect the connec-
tors from the three main PCB socket receptacles. To install a replacement power supply, (en-
sure the correct power supply was ordered as a replacement: 120/220/240 V ac or 24 V dc) align
the three corner holes over the standoffs and the three connectors over the main PCB socket re-
ceptacles before carefully mating the two boards together. Fasten the power supply board to the
standoffs with the three retaining screws. Do not use the screws to pull the boards together.
The power supply does not have to be removed to replace the fuse. The fuse can be accessed on
the power supply when the main PCB is removed from the instrument. To remove a suspected
blown fuse, pry off the plastic fuse cover cap and pull the fuse from the holder prongs. To install
a new fuse, gently snap it into each end of the holder prongs and push on the cover cap. Fuses
for the two power supply types are as follows: for the 120/220/240 V ac power supply - 1 A, 250
V, Fast Blow Schurter Type 034.3930, and for the 24 V dc power supply - 3 A, 250 V, Slow
Blow BEL Type 5TT3.
When replacing parts, should technical assistance be required, contact the nearest MMA field office.
NECESSARY ORDERING INFORMATION
When communicating with MMA for replacement of the main PCB,
reference the unit’s serial number to ensure the correct replacement
assembly is supplied. The necessary ordering information is provided
on the instrument data tag and on the manufacturing specification sheet
supplied with that particular controller.
In the event of a hardware malfunction, a replacement PCB can be quickly substituted for the defec-
tive assembly to minimize downtime. Contact
MMA for instructions before returning equipment.
The defective PCB should be carefully packaged and returned, shipping charges prepaid, to the Re-
pair Dept. of
MMA . Do not wrap PCBs in plastic, as it can cause static damage. It is suggested
that the defective PCB be returned in the special bag in which the replacement module was sup-
plied.
53ML5100 Manual Loading Station
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