
Troubleshooting
2-88
Test 408.4 — Correction factor
Type
Circuit Exercise
Fault message
None
Description
This test is the same as test 408.3 except that no measurement is taken.
Drawing reference
Analog Board; 2002-100
Bit patterns
Test 408.5 — Signal stored for test 408.6
Type
Circuit Exercise
Fault message
None
Description
The SELFTEST control line turns ON Q425 and forces the voltage on NET1 (R488) to ground.
The response of R488 pin 4 is stored in C439. This test uses the same path as test 408.1 except
as follows: when the SELFTEST control line forces the divider voltage to zero, it also generates
a one-shot pulse 5µs after SELFTEST goes low. This pulse turns Q414 on and stores the voltage
on C439. The 5µs delay that controls U425 and Q414 is generated by U402. No measurement
is made during this phase.
Drawing reference
Analog Board; 2002-100
Bit patterns
Bit pattern*
Register
—U400—
01111101
—U811—
00001101
—U224—
00010111
—U432—
00000000
—U810—
00000011
—U206—
01110000
—U203—
10001110
—U411—
00111011
—U809—
11100111
—U207—
11001111
—U221—
11101001
—U406—
01101110
AD_STB
MUX_STB
R1_STB
R2_STB
*Bits associated with register IC terminals as follows:
Q
Q
Q
Q
Q
Q
Q
Q
87654321
87654321
87654321
87654321
IC pins: Q8=11, Q7=12, Q6=13, Q5=14, Q4=7, Q3=6, Q2=5, Q1=4.
Bit pattern*
Register
—U400—
01111101
—U811—
00001101
—U224—
00010111
—U432—
00000000
—U810—
00000011
—U206—
01110000
—U203—
10001110
—U411—
00111011
—U809—
11100111
—U207—
11001111
—U221—
11101001
—U406—
01101100
AD_STB
MUX_STB
R1_STB
R2_STB
*Bits associated with register IC terminals as follows:
Q
Q
Q
Q
Q
Q
Q
Q
87654321
87654321
87654321
87654321
IC pins: Q8=11, Q7=12, Q6=13, Q5=14, Q4=7, Q3=6, Q2=5, Q1=4.
Содержание 2002
Страница 1: ...Model 2002 Multimeter Repair Manual Contains Servicing Information...
Страница 125: ...Troubleshooting 2 112...
Страница 145: ...A Specifications A 1...