Keithley 2002 Repair Manual page 96

Test 406.6 — Sample and hold circuit
Type
Fault message
Description
Drawing reference
Components
Bit patterns
Pass/Fail
Sample and hold
This test is the same as test 406.5, but the value is stored for use in comparison calculation in
this test phase. The measurement compares the actual difference in the DAC voltages 406.1-
406.4 with that found via the sample and hold circuit tests 406.3-406.6.
Analog Board; 2002-100
Q409, U402, U426, U428, and associated components.
—U811—
00001101
—U224—
00010111
—U400— —U432—
01011101 10000000
*Bits associated with register IC terminals as follows:
Q Q Q Q
87654321 87654321
IC pins: Q8=11, Q7=12, Q6=13, Q5=14, Q4=7, Q3=6, Q2=5, Q1=4.
Bit pattern*
—U810—
00000011
—U206—
01110000
—U203—
10001110
—U411—
11111011
Q Q Q Q
87654321 87654321
Troubleshooting
Register
—U809— AD_STB
11100111
—U207— MUX_STB
11001111
—U221— R1_STB
11101001
—U406— R2_STB
01001101
2-83