Troubleshooting Procedure - Keithley 7036 Instruction Manual

Service Information

Troubleshooting procedure

Table 5-4 summarizes switch card troubleshooting.
WARNING
Lethal voltages are present within the
Model 7001/7002 mainframe. Some of
the procedures may expose you to haz-
ardous voltages. Observe standard
safety precautions for dealing with live
circuits. Failure to do so could result in
personal injury or death.
Table 5-4
Troubleshooting procedure
Step Item/component
1 GND test point (C114)
2 +6V pad (Q101, pin 2)
3 +5V pad (C103)
4 +15V pad (R101)
5 +V pad (C114)
6 U107, pin 6
7 U107, pin 5
8 U101, pin 7
9 U101, pin 2
10 U101, pin 3
11 U101-U105, pins 10-18
*+3.5VDC present at +V pad under steady-state conditions. This voltage rises to +5.7VDC for about 100msec when relay conf guration is changed.
5-12
Required condition
+6VDC
+5VDC
+15VDC
+3.5VDC*
ID CLK pulses
ID DATA pulses
STROBE pulse
CLK pulses
DATA pulses
Low with relay energized; high
with relay de-energized.
CAUTION
Observe the following precautions when
troubleshooting or repairing the switch
card:
To avoid contamination, which could
degrade card performance, always han-
dle the card only by the handle and side
edges. Do not touch edge connectors,
board surfaces, or components on the
card. Also, do not touch areas adjacent
to electrical contacts on connectors.
Use care when removing relays from the
PC board to avoid pulling traces away
from the circuit board. Before attempt-
ing to remove a relay, use an appropri-
ate de-soldering tool such as a solder
sucker to clear each mounting hole
completely free of solder. Each relay pin
must be free to move in its mounting
hole before removal. Also, make certain
that no burrs are present on the ends of
the relay pins.
Comments
All voltages referenced to digital ground
(GND pad).
Relay voltage.
Logic voltage.
Relay bias voltage.
Regulated relay voltage.
During power-up only.
During power-up only.
End of relay update sequence.
During relay update sequence only.
During relay update sequence only.
Relay driver outputs.