Gasboy CFN Series Diagnostic Manual - Manual (Page 160)

GASBOY CFN Series
4-44 03/19/04
Possible Cause Checks Corrective Action
Incorrect ICR address setting. Do a self-test # 8 at the ICR. If self-test # 8 doesn't show
the correct address, set the S2
switches to the proper address
setting and press reset switch
S1.
If self-test # 8 still shows an
incorrect address, replace the
Reader Terminal CPU board.
Defective RS-485 driver IC in
ICR. Check if L1 is flashing. If L1 is not flashing, replace IC
(U6).
Replace the Reader Terminal
CPU board if replacing U6
didn't fix the problem.
Defective RS-485 driver IC in
ICR. Check if L2 is flashing. If L1 is not flashing, replace
IC.
Defective RS-485 protection
PCB in ICR. Using an oscilloscope,
measure between screw
terminals 1 and 2 on TB1 of
the ICR RS-485 protection
PCB. Replace the RS-485 protection
PCB if a 5VDC square wave is
not measured between pins 1
and 2 when L1 is flashing.
Incorrect wiring between the
ICR and the RS-485 junction
box. Using an oscilloscope,
measure between screw
terminals 1 and 2 on TB1 of
the junction box RS-485
protection PCB. Repair any shorts, opens, or
crossed wires if a 5VDC
square wave is not measured
between pins 1 and 2 when L1
is flashing.
Defective RS-485 Protection
PCB in junction box. Using an oscilloscope,
measure between pins 1 and 2
of P3 of the junction box RS-
485 protection PCB. Replace the RS-485 protection
PCB if a 5VDC square wave is
not measured between pins 1
and 2 on P3.
Defective RS-485 receiver IC
or site controller CPU board. Check if any devices are up.
Check if L4 (SC I CPU board)
or L3 (SC II CPU board) is
flashing.
If all devices on island loop are
down, then check LED's and
proceed as directed.
If L4 (SC I) or L3 (SC II) is not
flashing, replace U2 (SC I) or
U4 (SC II).
Replace the site controller
CPU Board if replacing the
RS-485 receiver IC didn't fix
the problem.
(Continued)