Power Board Troubleshooting; Control Board Troubleshooting - Bosch ACS 753 Repair Instructions

ACS 753, ACS 763, ACS 863 Service Manual

Power Board Troubleshooting

1. Possible reasons to replace the power
board:
• No power to any components.
• A solenoid won't open.
• Compressor and fan won't start.
• Vacuum pump won't start.
• A function does not start or finish a
process.
2. Do not replace the power board for these
issues:
• Display has lines, missing characters,
etc.
• Repeated read errors.
• Repeated communication errors.
• Display is blank at power up, contrast
can't be adjusted, and power has been
verified.
The best way to troubleshoot is to go into the
diagnostic menu:
• If you are able to switch a solenoid or
relay on and off, the output portion of the
board is likely okay.
• If the fan, compressor, or vacuum pump
is selected it should receive power.
Pressures can be verified with a gauge at
the accumulator port, low-side hose, and
by accessing the tank. The tank pressure
transducer can be checked by charging a hose
and comparing to the low-side transducer or
the gauges. They should be reasonably close
initially, but the gauge or low-side reading
should drop quickly if the tank is warm.
Robert Bosch GmbH
Diagnostics and Testing

Control Board Troubleshooting

1. Possible reasons to replace control board:
• Repeated read errors.
• Repeated Communication errors.
• Keys don't read (after verifying keypad).
NOTE: Before reflashing, make sure the unit
has the latest software version installed. If
the software version is current. Do not reflash
controller if updating the software solves the
problems, unless a TSB indicates reflashing
is needed.
2. Do not replace the control board for these
issues:
• A solenoid will not open.
• A motor won't start.
• Scale is out of calibration, (overcharge/
undercharge etc).
• The display is dim or dark (unless it can
not be adjusted).
• A pressure reading is wrong.
• High pressure, air purge time out, etc.
• A function doesn't start or complete
(Recovery, Charge Tank Fill etc).
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SP00D00609 2018-03-26