Agilent Technologies 6621A, Service Manual

Page: 133 / 156

Figure 6-2. GPIB Board, Component Location
6-7
NOTES:
This surface-mount GPIB assembly applies to models
starting with the following serial numbers and up:
662
1
A 373
7
A03
0
8
6
-up
662
2
A 373
6
A0
40
2
1
-up
662
3
A 373
6
A0
5451
-up
662
4
A 373
5
A
13
8
01
-up
Electrically and functionally, this assembly differs
somewhat from the previous GPIB assembly. The
surface-mount GPIB assembly is not repairable to the
component level, so a parts lists is not provided.
Signature analysis repair is not available for the
surface-mount GPIB assembly.
This board has a 4-position switch on it (located next
to U206) that replaces the function of connector P201
described on page 4-8 of this manual. The switch
selects the following functions:
Switch 1 - the model function. ON selects models
6621A, 6622A, 6623A, 6624A, and 6627A. OFF
selects models 6625A, 6626A, 6628A, and 6629A.
As-shipped position = O
N
Switch 2 - selects calibration lockout. ON locks out
front panel calibration. OFF enables front panel
calibration.
As-shipped position = OFF
Switch 3 - selects skip self test. ON skips self test at
turn on. OFF enables self test at turn on.
As-shipped position = OFF
Switch 4 - not used
662
7
A 373
5
A
023
56-up