Keithley 194 Instruction Manual page 205

MAINTENANCE
Table 7-12. I/O Board Checks
Step ItemlComponent
1
2 U404, lJ407, U410, pin 25
3 u404, u407, u410,
pins 26-33
4 U404, pins 2-17
5 U407, pins 2-15
6 U405, pins 11-18
7 U406, pins 11-18
8 U408, pins lo-16
9 U409, pins lo-16
10 U410, pins lo-15
11 U410, pin 2
12 U410, pin 3
13 U410, pin 4
14 U410, pin 5
15 U410, pin 6
16 LJ410, pin 7
17 U410, pin 8
18 Front panel
19 VOLTAGE INPUT jack
20 XY mode programming
21
22
U412-U414, pins 3-8, B-18,
U4l5, pins 3-8, W
U412-U415, pin 1
23 U416, pins l-12
24 U4l7, pins 1-2
25
U4l5, pin 19
26
11007
27 J1006
28 11005 Pulse at XY mode transmission interval. Z output pulse.
All voltages referenced to digital
Check for presence of data pulses.
Positive going pulses.
Display segment driver data.
Positive going pulses. Display digit driver data.
Positive going pulses. Display segment data.
Positive going pulses. Display segment data.
Sawtooth waveform.
Display digit data.
Sawtooth waveform.
Display digit data.
Negative going pulses. Keyboard scan data.
Pulses present when ZERO button is Returned key board data.
pressed.
Pulses present when TRIGGER button Returned keyboard data.
is pres&d.
Pulses present when LEVEL key is
pressed.
Returned keyboard data.
Pulses present when RATE key is
pressed.
Returned keyboard data.
Pulses present when SHIFT key is Returned keyboard data.
pressed.
Pulses present when TRMS key is
pressed.
Returned keyboard data.
Pulses present when RECALL key is
Returned keyboard data.
pressed.
Program 1000 samples, 10psec rate, con-
tinuous trigger.
Apply time varying signal. Select appropriate range.
Proeram X and Y 1OV full scale, enter
XY &ode, trigger XY output with XY
TRIG.
Data bus pulses. Check for stuck bit on data
(DO-D7).
Negative going pulse while XY mode is Analog output latch enable pulses.
running.
Varying data pulses. X output digital data.
Varying data pulses. Y output digital data.
Pulse at XY mode transmission interval. Z blanking pulse.
Positive-going ramp. x analog output.
Analog signal (depends on measured Y analog output.
signal).
7-32