Tektronix TCP300A, User Manual

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Troubleshooting and Error Codes
Table 6: Troubleshooting (cont.)
Problem Remedy
Degauss takes longer than 10 seconds Probe is attached to an energized circuit. Disconnect probe from circuit and retry.
Probe is faulty - Probe transformer (defective Hall device with excessive noise or drift)
may cause this symptom. May also be caused by a shorted or open wire in the probe
cable assembly.
Defective main board - If the probe is not the cause, then it is most likely a defective
main board in the ampli
fi er.
Cannot make a current measurement -
no measurement output from ampli
fi er
Current Probe is not locked. Lock the current probe.
Current Probe is improperly connected to the ampli
fi er input connector.
Ampli fi er COUPLING is set to AC. Set the COUPLING to DC.
A Degauss/Autobalance routine has not been completed successfully on the system.
Degauss the probe.
Oscilloscope/Ampli
fi er is not set to an appropriate sensitivity setting.
Defective interface cable (between oscilloscope and ampli fi er).
MANUAL BALANCE will not adjust Oscilloscope or ampli fi er input coupling not set to DC. MANUAL BALANCE buttons only
function when the ampli fi er is in the DC coupling mode.
Oscilloscope/Ampli fi er is not set to an appropriate sensitivity setting.
Stray DC component in measurement Degauss the probe using the PROBE DEGAUSS AUTOBALANCE button. (The Current
Probe has been overloaded, dropped, or exposed to magnetic
fi eld.)
You can use the MANUAL BALANCE buttons to null out any residual DC offset after
performing a Probe Degauss Autobalance routine.
Measurements are inaccurate Degauss the probe.
The ampli
fi er output is not terminated into 50 Ω load. Set the input impedance of
oscilloscope to 50 Ω or connect a 50 Ω feedthrough termination at the oscilloscope input.
Do not attach the termination at the ampli fi er output.
The measurement exceeds the maximum continuous current or Ampere-second product
ratings of the Current Probe.
Ampli
fi er or current probe out of calibration. (See the service manual for performance
veri fi cation procedures.)
Defective current probe transformer.
Measurements roll off at high
frequencies The oscilloscope bandwidth limit is turned on. Verify that the bandwidth limit switch on
the oscilloscope is set to the desired bandwidth position.
(Be careful not to exceed the frequency limit of the probe used. Frequencies above the
probe design may cause overheating and damage to the probe.)
Measurements exhibit excessive noise
Current Probe is not locked. Lock the current probe.
Current Probe is improperly connected to the ampli
fi er input.
Ampli fi er output is not terminated into 50 Ω load. Set input impedance of oscilloscope
to 50 Ω or connect a 50 Ω feedthrough termination at the oscilloscope input, not at the
ampli fi er output.
Defective current probe transformer.
TCPA300/400 Ampli fi ers and TCP300A/400 Series Current Probes User Manual 43