Section 4. Service Sheets; Circuit Description; Troubleshooting Aids - Agilent Technologies 4284A Service Manual

4-1. INTRODUCTION
This section contains a service sheet for each o f the HP 4284A's PC board assemblies.
Each service sheet is organized into six parts: Circuit Description, Troubleshooting Aids,
Board Connector Pin Assignments, Replaceable Parts List, Component Location Drawing,
and Schematic Diagram.

4-2. CIRCUIT DESCRIPTION

The circuit description gives a detailed functional circuit description of each board.

4-3. TROUBLESHOOTING AIDS

The troubleshooting aids provide information t o help you troubleshoot problems i n the
HP 4284A. Usually the troubleshooting aids consists of a list of jumpers, a list of test points,
and troubleshooting information. The jumper list shows the strapping configuration for each
jumper. T h e test point list gives a description of the signal at each test point. T h e trouble-
shooting information includes waveforms for troubleshooting the board, and the measure-
ment setup for viewing the waveform is listed next to the waveform figure, refer to Figure 4 -
1.
Setting up the oscilloscope:
(1) S e t the oscilloscope inputs to DC coupled (1 mn).
(2) T h e settings (using a 1:1 probe) for channel A and B, and the time base setting are
displayed with the waveform, refer to Figure 4-1. When a 10:1 divider probe is used,
the channel A and B settings must be multiplied by 10.
CHANNEL A C H A N N E L B
Ve r t i c a l S e t t i n g V e r t i c a l S e t t i n g S e t t i n g
CHANNEL A
Waveform
CHANNEL B
Waveform
SECTION 4
SERVICE SHEETS
T i
5.00 Vichy 5 . 0 0 V/dr., 2 0 0 n s r d l v
{
Figure 4-1. Oscilloscope Setup
4-1
m e Base
spaqs 33