Service Sheets; Circuit Description - Agilent Technologies 4284A Service Manual

4-1 . INTRODUCTION
This section contain s a service sheet for each of the HP 4284A' s PC board assemblies.
E ach service s heet is organized into six parts: Circuit Description, Troubleshootin g Aids ,
Board Connector P i n Assignments, Replaceable Parts List, Component Location Drawing,
and Schematic Diagram .

4-2. CIRCUIT DESCRIPTION

The circuit description g ives a detailed functional circuit description of each board .
4-3. TROUBLESHOOTING AIDS
The troubleshooting aids provide information to help you troubleshoot problems in the
HP 4284A. Usually the troubleshooting aids consists of a list of jumpers, a l ist of test points,
and troubleshooting information. The j umper list shows the strapping config uration for each
jumper. The test point list g ives a description of the signal at each test point. The trouble­
shooting info rmation includes waveforms for troubleshooting the board, and the m easure­
ment setup for viewing the waveform is listed next to the waveform figure, refer to Figure 4-
1 .
Setting up the oscilloscope:
( 1 ) Set the oscilloscope in puts to DC coupled (1 MQ).
(2) The settings (using a 1 : 1 probe) for channel A and B, and the time base setting are
d isplayed with the waveform, refer to Fig u re 4-1 . When a 1 0: 1 divider probe is u sed ,
the channel A and B settings m ust be multiplied by 1 0.
CHANNE L A
Wave form
CHANNEL B
Waveform
SECTION 4

SERVICE SHEETS

Figure 4-1 . Oscilloscope Setup
4-1