GE Corometrics 250cx Series, Service Manual, Page: 151 / 252

Revision C 250cx Series Maternal/Fetal Monitor 5-11
2036947-001
Troubleshooting: Diagnostic Control Screen
5. Open the recorder door.
6. Support the printhead by reaching in through the recorder door, then remove the
two screws on top of the printhead.
7. Pull the printhead down and out through the recorder door with the harness still
attached.
NOTE
If you are familiar with other Corometrics monitors, be
assured that the four pressure springs are held captive and
will not fall out.
8. Remove the harness cable from the printhead and retain for use with
replacement printhead.
Replacing the Printhead
Use the following procedure for installing a 250cx Series Monitor printhead:
1. Turn off the 250cx Series Monitor and disconnect the power cord from the
monitor.
2. Carefully remove the new printhead from the packaging; do not touch any of
the contact pins. Record the voltage rating marked on the decal affixed to the
bottom of the printhead. This value is the VHEAD voltage. The voltage rating
should be marked over the old voltage rating on the printhead bracket.
3. Re-connect the harness cable to the printhead.
4. Slide the new printhead into position through the recorder door and under its
bracket. Push on the center of the printhead to ensure it is pushed all the way
back.
5. Align the printhead with the front holes in the bracket and replace the two
screws.
6. Re-connect the harness cable to the Recorder Board at J3.
7. Connect the positive lead of a voltmeter to TP1 on the Recorder Board; connect
the negative lead to TP2.
8. Re-connect the monitor power cord and then turn on the monitor.
9. Press the
Record
button to turn on the recorder.
10. Adjust R2 on the Recorder Board until the reading on the digital voltmeter is
within ±100 mV of the VHEAD voltage stamped on the printhead.
11. Access the Diagnostic Control service mode screen and run the recorder test to
check the printing of vertical lines. (Refer to
“Diagnostic Tests”
on page 5-3.)
If light printing occurs, refer to the instructions under
“Horizontal Offset
Adjustment”
on page 5-9.
12. Replace the top cover and secure all nine screws.