Analog Circuitry Checks; Battery Replacement - Keithley 2425 Service Manual

4-16 Troubleshooting

Analog circuitry checks

Table 4-4 summarizes analog circuitry checks.
Table 4-4
Analog circuitry checks
Step
2
3
4
5
6
7
8
9
1
Measured with respect to FCOM (TP500).
2
Measured with respect to OCOM (TP501).

Battery replacement

WARNING
The volatile memories of the Model 2425 are protected by a replaceable battery when
power is off. Typical battery life is approximately 10 years. The battery should be sus-
pected if the instrument no longer retains buffer data or user-defined operating parameters
such as instrument setups, source memory, and math expressions. If the battery is absent
or totally exhausted, the display will show the "Reading buffer data lost" message shortly
after the Model 2425 is switched on.
The battery is a 3V wafer-type lithium cell, Panasonic type BR-2330 or equivalent
(Keithley part number BA-46), which is located on the digital board. Replacement of the
battery requires removal of the case cover and analog board assembly. (See Section 5.)
Item/component
1 TP200
1
TP201
1
TP202
1
TP203
1
TP213
1
TP218
2
TP219
2
TP214
2
TP232
1
Disconnect the instrument from the power line and all other equip-
ment before changing the battery.
Required condition
>100V voltage protection
SOURCE +10V
SOURCE +10V (SVMI)
SOURCE +10V
SOURCE +10V
OUTPUT COM
OUTPUT COM
SVMI, OUTPUT ON, 20V
Bench defaults
Model 2425 Service Manual
Remarks
-13V ±1V
-5V ±0.5V
-10V ±1V
-10.5V ±1V
0V ±0.1V
7V ±0.7V
7V ±0.7V
20V ±0.5V
6.4V ±0.6V