Fluke PM3082 Service Manual page 485

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8.12.4.7 Repair tools /D AC
Thoughout the oscilloscope there are several digital-to-analog converters (DAC's) that are controlled
by the microprocessor. The 'REPAIR TOOLS' menu enables to select a certain DAC output (via
TRACK) and to determine the output voltage (via A) at this output. After having opened the
instrument, the voltage can be measured with a voltmeter or oscilloscope. The DAC output voltage
range is between 0 ... 10V (1 ... 4V for D1112). This test is not influenced by softkey 'on off'. A DAC
VALUE once changed returns to the old value if the menu is left.
The selections with the TRACK rotary have the configuration X.Y. The character X points to a certain
DAC IC. The table shows the relation:
X-value IC reference number
0.Y
N9001
2.Y
N9003
3.Y
N1001
4.Y
N8005
6.Y
N9002
7.Y N2002
8.Y
D1112
The character Y points to a certain output within the selected DAC IC. The table shows this for N9001,
N9002, N9003 and N8005 on unit A1:
Y-value Pin
number N9001
X.O 11
X.1
13
X.2 14
X.3
15
X.4
16
X.5 17
X.6
18
X.7
20
Note: for explanation of signal names, refer to chapter 5.1.2
For N1001 and N2002 (unit A2) refer to the table below:
Y-valuePinName/function of generated signal:
Y-value
X.O
X.1
X.2
X.3
X.4
X.5
X.6
X.7
Note: for explanation of signal names, refer to chapter 5.2.2
Unit number
A1
A1
A2
A1
A1
A2
A3
Name of generated signal:
N9002
PAIOFFSTRG AT3LFCAL
PA1OFFSET AT30FFSET
AT 1LFCAL AT3LOOPCAL
AT1 OFFSET PA20FFSTRG
AT1LOOPCAL PA20FFSET
ATCALO AT2LFCAL
ATCAL1 AT20FFSET
ATCAL2 AT2LOOPCAL
Name/function of generated signal:
Pin
N1001
number
LF sq. wave
11
LF sq. wave
13
Gain
14
HF sq. wave
15
Offset
16
Offset
17
MF sq. wave
18
MF sq. wave
20
CORRECTIVE MAINTENANCE PROCEDURES
Name of circuit diagram
Control circuits
Control circuits
Final Y preampl. + control
Time base logic
Control circuits
Final X amplifier + control
Potentiometer DAC + IEEE
N9003
DLDOFFSET
PA40FFSTRG
PA40FFSET
AT4LFCAL
AT40FFSET
AT4LOOPCAL
PA30FFSTRG
PA30FFSET
N2002
ASTDR
DARK
XHFADJ
XTRAGC
XCRTGCL
XCRTGCH
XCRTOFL
XCRTOFH
N8005
TBINTTRAT-XA
DTBVAR
DSOCALD
DSOCALM
DTRSEN
MTRTVMODE
MTRBAL
MTRSEN