Keysight 3458A - Page 74

3 Disassembly/Assembly Procedures and Parts List
74 Keysight 3458A Assembly-Level Repair Manual
Removal procedure
1 Use the Covers removal procedure in this section of the manual to remove the
3458A top cover and top shield. It is not necessary to remove the bottom cover
and bottom shield.
2 Set the 3458A on your workbench with the top facing you.
3 Unplug the following wires and cables. Unless otherwise noted, all wires and
cables are unplugged from the DC Circuitry assembly.
a Blue wire from the metal Inguard shield. This wire is not plugged into the
DC Circuitry assembly, but must be unplugged to remove the assembly.
Move the wire out of the way.
b Gray wire from the metal Inguard circuit ground. This wire is not plugged
into the DC Circuitry assembly, but must be unplugged to remove the
assembly. Move the wire out of the way.
c Yellow wire from P202. Move the wire out of the way.
d Orange wire from P7. Move the wire out of the way.
e Gray wire from P6. Move the wire out of the way.
f Black and white wires from P8 and P9, respectively. The black and white
wires form a white cable. Move the cable out of the way.
g Gray 20 pin cable from P3. Move the cable out of the way.
4 Use the #TX 10 Torx driver to remove the two screws from the DC Reference
assembly.
5 Use the #TX10 Torx driver to remove the eight screws from the DC Circuitry
assembly.
6 Use the plastic board extractor on the DC Circuitry board to unplug the board
from the inguard chassis. Then completely remove the board.