HP 437B Service Manual

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Troubleshooting
Note
HP 437B
Service Sheet BD1
Test Equipment
Digitizing Oscilloscope ........... cc cc cece eee eeees HP 54201A
PROD Sen 3 dso sels. OA ccidnn shichdacleaitee daa wade dade’ HP 10081A
Sensor Cable .......... 0c. ccccceecceecucseuveuveaes HP 11730A
Range Calibrator ........... ccc ccc ccc e cece sev euees HP 11683A
Digital Voltmeter (DVM) ......... 0... cece ccc ee ees HP 3456A
TTL/CMOS Logic Probe ...............cceccceu venues HP 545A
Introduction
This troubleshooting procedure assumes that the Installation Checklist
(Paragraph 2-4 in Section 2, Installation) has been performed and that the
proper line voltage and fuse have been selected.
The troubleshooting checks in this section are designed to isolate a
malfunction to a schematic diagram as quickly as possible. The tests progress
from general "over-all" tests to specific tests of certain areas of the Power
Meter.
The HP 437B Power Meter consists of 4 major sections; the digital board, the
analog board, the keyboard/display section, and the power supply.
The digital board consists of the digital circuitry of the Power Meter and the
power supply. The digital board is located underneath the Power Meter’s top
cover. The analog board is located underneath the Power Meter’s bottom
cover.
The troubleshooting procedure is separated into three checks as follows:
1. Power Supply Check
2. Digital Board Check
3. Analog Board Check
Some malfunctions of the Power Meter may cause the display to fail. To aid
troubleshooting when this situation occurs, the digital board has a set of
service LEDs (D0 to D7). These LEDs blink in certain patterns to indicate
various states and conditions of the Power Meter. These LEDs will be
referred to in several places in this procedure.
SERVICE §.21

HP 437B Specifications

General

Brand	HP
Model	437B
Category	Measuring Instruments
Language	English