Keithley 2015 Service Manual

4-20 Troubleshooting
Digital circuitry checks
Digital circuit problems can be checked out using Table 4-4.
Table 4-4
Digital circuitry checks
Step Item/component Required condition Remarks
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
Power-on test
U152 pin 14
U152 pin 28
U135 pin 48
U135, lines A1-A23
U135, lines D1-D15
U135 pin 44
U159 pin 13
U159 pin 14
U158 pins 34-42
U158 pins 26-31
U158 pin 24
U158 pin 25
U135 pin 84
U135 pin 91
U135 pin 90
U135 pin 89
RAM OK, ROM OK.
Digital common.
+5V
Low on power-up, then goes
high.
Check for stuck bits.
Check for stuck bits.
14.7456MHz
Pulse train during RS-232 I/O.
Pulse train during RS-232 I/O.
Pulse train during
IEEE-488
I/O.
Pulses during IEEE-488 I/O.
Low with remote enabled.
Low during interface clear.
Pulse train.
Pulse train.
Pulse train.
Pulse train.
Verify that RAM and ROM are
functional.
All signals referenced to digital
common.
Digital logic supply.
MPU RESET line.
MPU address bus.
MPU data bus.
MPU clock.
RS-232 RX line.
RS-232 TX line.
IEEE-488 data bus.
IEEE-488 command lines.
IEEE-488 REN line.
IEEE-488 IFC line.
ADRXB
ADTX
ADCLK
ADTS

Keithley 2015 Specifications

General

Brand	Keithley
Model	2015
Category	Multimeter
Language	English