Service manual

Test Tools

4-2

3Test Tools

Two troubleshooting tools are provided with each instrument:

• patient cable test tool (M1770-87908)

• front end and transmission test tool (M1770-87909, Rev. B)

Patient Cable Test Tool (M1770-87908)

This tool is attached inside the battery compartment, beneath the battery. To locate it, open

the battery compartment door and lift the battery.

This tool is used to short the lead wires together to test lead wire integrity. To test the

leads, plug all ten lead wire posts into the holes of the tool and print an ECG. If all leads

print clear, solid flat lines, the lead wires are intact.

Front End and RS-232 Port Test Tool (M1770-87909, Rev. B)

This tool is located on the lower side of the printer door. To remove it, open the printer

door and reach underneath it. The tool has two test plugs, one used to test the instrument

signal path, and one used to test the cardiograph’s RS-232 port.

Testing the Instrument Signal Path

To test the instrument signal path, plug the larger connector into the patient cable

connector on the front of the cardiograph. Print an ECG. If the front end is operating

properly, all leads will show clear, solid flat lines with little or no noise.

You can use the patient cable test tool and the front end test tool to isolate patient cable

problems and cardiograph problems.

Testing the Cardiograph’s RS-232 Port

To test the cardiograph’s RS-232 port, plug the smaller connector into the RS-232 port, in

place of the modem. Run the extended self-test described in Chapter 2. The modem test

will pass if the cardiograph RS-232 port is operating properly. This can help differentiate

between cardiograph problems, and cable or modem problems.

You can use the front end and RS-232 port test tool to isolate modem problems and

cardiograph problems.

The RS-232 port test connector is available only on Revision B of the M1770-87909.

NOTE