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Troubleshooting

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Bit patterns

Test 405.3 — Small positive DAC V for X10 gain comparison

Type

Circuit Exercise

Fault message None

Description DAC U433 and op amp pair U430 are set up to generate +0.190 VDC at PRECOMP+. This sig-

nal follows the same path as test 405.1. This test has the same purpose as test 405.1, but the new

test value is used for test 405.4.

Components Analog Board; 2002-100

Bit patterns

Test 405.4 — Absolute value X10 gain (non-inverting)

Type Pass/Fail

Fault message Absolute value gain = 10

Description DAC U433 and op amp pair U430 are set up to generate +0.190 VDC at PRECOMP+. This sig-

nal follows the same path as test 405.2.

Drawing reference Analog Board; 2002-100

Bit pattern* Register

—U400—

01011100

—U811—

00001101

—U224—

00010111

—U432—

10001101

—U810—

00000011

—U206—

01110000

—U203—

10001110

—U411—

11111111

—U809—

11100111

—U207—

11001111

—U221—

11101001

—U406—

01001111

AD_STB

MUX_STB

R1_STB

R2_STB

*Bits associated with register IC terminals as follows:

QQQQQQQQ

87654321 87654321 87654321 87654321

IC pins: Q8=11, Q7=12, Q6=13, Q5=14, Q4=7, Q3=6, Q2=5, Q1=4.