American Magnetics 187 Self-Compensating Liquid Level Controller - Manual (Page 64)

53
Service
Troubleshooting Hints
d. Replace the fuse and securely fasten the instrument top cover.
Reconnect the power-cord.
3. Verify the input voltage selector switch on the instrument’s printed
circuit board is in the proper position for the available input power.
Checking the input voltage selector requires removal of the top
cover of the instrument. Observe the same safety procedures as
presented in step 2, above.
4. If the display appears blank but the instrument power-up appears
otherwise normal (all the LEDs energized), then the contrast of the
LCD display may need adjustment. The LCD display should always
be visible (especially when looking up at the unit), but may be only
faintly visible if set to a low contrast percentage. See paragraph
3.3.10.1 on page 23 for specific directions for adjusting the display
contrast.
5.2.2 The Model 187 does not remember the alarm setpoints after
power is removed.
Warning
This procedure is to be performed only when the instrument is
completely de-energized by removing the power-cord from the power
receptacle. Failure to do so could result in personnel coming in
contact with high voltages capable of producing life-threatening
electrical shock.
1. Ensure the instrument is de-energized by disconnecting the power
cord from the power source. Disconnect the power cord from the
connector located on the rear panel of the instrument.
2. Remove the instrument top cover and replace the computer
memory backup battery, BT1.
Note
When replacing the battery, replace with a 3.6 volt AA-size lithium
cell (International size reference: ER14505). Comply with the
polarity markings adjacent to the battery holder on the printed
wiring board.
Warning
Do not attempt to recharge the Lithium cell. Attempts at recharging
may cause the cell to vent or explode.