Zeiss humphrey HFA II-i series, Field Service Manual

Page: 162 / 521

Troubleshooting Humphrey Field Analyzer II - i
Confidential and Proprietary
Field Service Guide
5 - 12 52235C1105
Door Open:
When the door is opened (either latch unlocked), the printer stops printing, goes off line, sets
the Fault Line low, sets the Busy line high, and flashes the ERROR indicator.
Overvoltage Error:
If the +24 Vdc input is too high (+27 volts or greater), the printer stops printing, sets the
Fault line low, sets the Busy line high, flashes the ERROR indicator, and waits for the voltage
to drop to operating levels.
Under Voltage:
If the +24 Vdc input is too low (+21 volts or less) for a period of 625 ms or more, the
printer stops printing, sets the Fault line low, sets the Busy line high, flashes the ERROR
indicator, and waits for the voltage to return to +22 volts or higher before resuming normal
operation.
Over Temperature:
If the printhead temperature increases above a preset level, the printer runs slower than
specified to allow it to cool, and returns to normal speed when the temperature reaches an
acceptable level. If the printhead temperature exceeds operating levels, the printer stops
printing, sets the Fault line low, sets the Busy line high, flashes the ERROR indicator, and
waits for the temperature to drop to operating levels before resuming normal operation.
Brownout:
A brownout condition is defined as the +5 volt supply dropping below +4.5 volts. The
printer goes into reset and all data in its buffers is lost if a brownout occurs.