Selftest Sequence And Error Messages; Primary Interface - Agilent Technologies 6060B Service Manual

Type
GP-IB Controller
Signature Analyzer
Digital Voltmeter
Power Source
Logic Probe
Oscilloscope
Clip Leads

Selftest Sequence and Error Messages

The turn-on selftest sequence consists of tests on both the primary (GP-IB) and secondary (Electronic Load) interface
circuits. If the load fails the selftest, the input will remain disabled and the display should indicate the type of failure. Table
3-2 lists all of the selftest error codes that can appear on the front panel display and provides the appropriate troubleshooting
information.

Primary Interface

The turn-on selftest sequence of the primary microprocessor consists of two parts:
1. The selftest is performed by the primary microprocessor (U203) and starts when the primary clear ( PCLR ) signal goes
false (High). First, the RAM, ROM, and the microprocessor's internal timer selftests are performed. If any of these tests
fail, the front panel display will probably remain blank. The failure can be detected by measuring a square wave on the
SA_GATE line at TP201-8 (see Figure 3-2). The type of failure is indicated as follows:
10Hz square wave--indicates a RAM failure.
100Hz square wave--indicates a ROM failure.
1KHz square wave--indicates an internal timer failure.
Square waves will not have a 50% duty cycle. It is also possible for a selftest failure to ''lock-up" the microprocessor and
cause a blank front panel display and no error square wave to appear on the SA_GATE line. If ''lock-up'' occurs, try to
isolate the problem by performing the Primary Interface S.A. Tests or by replacing U203.
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Table 3-1 Test Equipment Required for Troubleshooting
Purpose
Communicate with the load via the GP-IB
Test most of the primary and secondary circuits
Check various voltage levels
Provide required input, bias GP-IB Board
Check data bus lines
Check waveforms and signal levels
Connect IC pins together
Recommend Model
Agilent 9825, Series 85, Series 200/300
Agilent 5005A/B
Agilent 3455A or 3456A
Agilent 6032A/6035A
Agilent 545A
Agilent 1741A
AP Products No. LTC