Troubleshooting
2-39
Test 300.2 – A/D mux, A/D buffer, 1.75V reference,
x5 gain
Pass/Fail
Cannot measure 8.75V ±0.875 at A/D IN.
This test switches the 1.75V reference (U327 output) through analog switch U318
(/2VREF pulled low) to the non-inverting input of Op Amp U322. Analog switch U318
(/X5 pulled low) is closed to use resistors R326 and R335 to obtain a gain of x5. Mea-
sure 8.75V (1.75V x 5) at A/D IN.
U318, R326 and R335.
DC_STB
Registers
R1_STB
Registers
R2_STB
Registers
U801
Q1:
0
Q2:
1
Q3:
1
Q4:
1
Q5:
1
Q6:
0
Q7:
0
Q8:
0
U307
Q1:
1
Q2:
1
Q3:
0
Q4:
1
Q5:
1
Q6:
1
Q7:
1
Q8:
1
U505
Q1:
0
Q2:
0
Q3:
1
Q4:
0
Q5:
0
Q6:
0
Q7:
0
Q8:
0
U800
Q1:
1
Q2:
1
Q3:
0
Q4:
0
Q5:
0
Q6:
0
Q7:
1
Q8:
1
U305
Q1:
1
Q2:
0
Q3:
1
Q4:
0
Q5:
0
Q6:
0
Q7:
1
Q8:
1
U500
Q1:
1
Q2:
1
Q3:
0
Q4:
1
Q5:
1
Q6:
1
Q7:
1
Q8:
1
U300
Q1:
1
Q2:
1
Q3:
1
Q4:
1
Q5:
1
Q6:
1
Q7:
1
Q8:
0
U302
Q1:
1
Q2:
1
Q3:
1
Q4:
1
Q5:
1
Q6:
1
Q7:
1
Q8:
0
U530
Q1:
0
Q2:
0
Q3:
0
Q4:
0
Q5:
0
Q6:
0
Q7:
0
Q8:
1
U303
Q1:
1
Q2:
0
Q3:
1
Q4:
0
Q5:
1
Q6:
1
Q7:
X
Q8:
X
U501
Q1:
1
Q2:
1
Q3:
0
Q4:
1
Q5:
1
Q6:
1
Q7:
X
Q8:
X
Note: Tables 2-10 through 2-12 provide functional descriptions of the register bits.
Type
Failure analysis
Description
High suspect
components
Bit pattern
Содержание 2001
Страница 1: ...Model 2001 Multimeter Repair Manual Contains Servicing Information...
Страница 129: ...Troubleshooting 2 116...
Страница 139: ...Replaceable Parts 4 4...
Страница 149: ...Replaceable Parts 4 14...
Страница 153: ...Replaceable Parts 4 18...
Страница 156: ...A Model 2001 Specifications A 1...
