Troubleshooting
Introduction
A
Select
Preset/local
Confirm
Lower Window - using 
Meas/Setup
Limits
Limits On
TTL Output
TTL Output On, Fail O/P Low
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| Yes |
| DVM reading |
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| No |
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| Power down meter. | ||||
Select |
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| Disconnect ac power and battery if fitted. | ||||||||
Fail O/P High |
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| Remove A2 Processor assy, as directed on page | |||||||
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| Use DVM to check resistance between J4 pin 42 | ||||
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| and Rmt I/O connector pin 4. | ||||
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DVM reading
Yes
No Fault found with Upper Window TTL Over Limit detection circuit - check user application/implementation
No
A2 Processor Assy
Defective
Yes |
| DVM reading |
| No |
| 450Ω +/- 10% |
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A4 Comms Assy
Defective
End
Agilent E4418B/E4419B Service Guide |
