Chapter 6 Backdating

Backdating Hardware

CHANGE 7 (Below Serial Number 3349A01906)

Page 5-7, Table 5-3.Replaceable Parts, under A1 (for the HP 53131A):

1Add 53131-00004; 9; 1; SHIELD UPPER; 28480; 53131-00004

1Add 53131-00005; 0; 1; SHIELD LOWER; 28480; 53131-00005

1Add 53131-00008; 3; 1; SHIELD CHASSIS; 28480; 53131-00008

1Add 53131-00009; 4: 1; GROUND CONNECTION 28480; 53131-00009

Change A4 (Standard) HP Part Number from 0950-2496 to 0950-2139.

Note: A4 AC Power Supply Assembly 0950-2496 allows 400 Hz operation from 100-120V.

1These shields were needed to reduce susceptibility to EMI. However, the shields are not needed on A1 Motherboard Assembly if the metalized front bezel is used in the Counter. Thus, when you order a new

A1 Motherboard Assembly (53131-60001, same part number as the old A1) for your HP 53131A Counter, you need to order a new metalized front bezel (53131-40003, same part number of the old non-metalized front bezel).

CHANGE 8 (Below Serial Prefix 3404A)

Page 5-7, Table 5-3.Replaceable Parts:

Change, under OPTION 001, A6 HP Part Number from 53132-60008 to 53132-60004.

Change, under OPTION 001, 1812-0931; OSCILLATOR-OVEN; to 1812-0932; OSCILLATOR-OVEN.

Change, under OPTION 010, A6 HP Part Number from 53132-60008 to 53132-60005.

Change, under OPTION 011, 10811-60111; OSCILLATOR-OVEN; to BLILEY OSCILLATOR-OVEN.

6

Assembly-Level Service Guide

6-7