Tektronix TPS2000B Series, Service Manual

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Maintenance
PROBE COMP Output When the oscilloscope is on and operating properly, the PROBE COMP output
should generate a square wave, approximately 5 V in amplitude, at a 1 kHz
frequency. Use the oscilloscope and the 10X probe to probe this output.
As shown in the following table, there are two cases of defects. Either the 1 kHz
signal is on and the I/O and Acquisition boards are both active and functionally
capable of performing an acquisition, or one of those two modules is not
performing correctly. While many different possible frequencies exist, all involve
detected failures on the Acquisition or I/O boards due to failure.
Signal at PROBE COMP Possible problem
1 kHz signal, no display Troubleshoot the display
Signal other than 1 kHz Troubleshoot the Acquisition board
No signal Troubleshoot the power supply
Using the Error Log Accessing the error log.
Failures that occur during the power-up diagnostics or
normal oscilloscope operation place an entry in the error log.
The error log list can be accessed any time by pushing the UTILITY button and
selecting
Options > Error Log . The following table lists the error codes.
Table 15: List of error codes
No. ID Description Probable cause
0 Battery Battery 1 alarm
1 Battery Battery 2 alarm
Battery hardware failure; replace
battery. If errors persist, contact
Tektronix.
2 Battery PIC Communication
3 Battery PIC HW Failure
May occur sporadically during
normal operation. If errors occur
repeatedly, a hardware failure may
exist. Contact Tektronix.
0 Diagnostics Diagnostics internal error
Contact Tektronix.
4 Diagnostics CH1 diagnostics failed Acquisition board or power supply
failure.
5 Diagnostics CH2 diagnostics failed Acquisition board or power supply
failure.
7 Diagnostics ADG421 diagnostics failed Acquisition board or power supply
failure.
12 Diagnostics CH3 diagnostics failed Acquisition board or power supply
failure
13 Diagnostics CH4 diagnostics failed Acquisition board or power supply
failure.
14 Diagnostics ADG421 #2 diagnostics failed Acquisition board or power supply
failure.
255 Software Software defect Contact Tektronix.
TPS2000B Series Digital Storage Oscilloscopes Service Manual 65