Appendix C: Operator Troubleshooting
1502C MTDR User Manual C–3
Error MessagesAny time the instrument displays an error message, the troubleshooting
procedures should be used to judge the extent and severity of the problem.
Some errors will still permit some kinds of measurements. If there is any doubt
about the ability to make a particular kind of measurement, do not make that
measurement until the problem has been corrected.
Option Port Device Not Responding...
Please check for correct installation.
– push MENU button to Continue –
This can occur anytime a chart printer, SP-232, or other Option Port device
requests attention from the TDR.
This error indicates that the TDR has received a signal indicating a request from
the Option Port device and either there is no device installed or the device is not
responding with a recognized ID byte when polled by the TDR.
This error might be very annoying because the Option Port is checked once each
time the TDR gets a waveform. If the TDR is being controlled by or through the
Option Port device, you will probably have to remove that device and make
manual measurements until the failure is corrected.
This type of failure will not affect measurements made manually.
If there is no Option Port device, there is probably a failure in the option port
logic circuitry on the main circuit board, or in the cable between the main board
and the Option Port connector. Refer the instrument to a qualified service
technician.
If the error is in response to a chart printer request, the PRINT switch on the
chart printer, or the wires to that switch, are probably bad or shorted to the
chassis or other ground point. Refer the chart printer to a qualified service
technician.
If the error is in response to another Option Port device, remove that device. If
the error ceases, have the device serviced. If the error persists, have the TDR
serviced.
ERROR: Acquisition Initialization
TYPE: Pulse gap > 3.75 dB