4-12
Troubleshooting
Analog circuitry checks
Table 4-4 summarizes analog circuitry checks.
*Measured with respect to FCOM (TP500).
**Measured with respect to OCOM (TP501).
Battery replacement
WARNING
Disconnect the instrument from the power line and all other equipment
before changing the battery.
The volatile memories of the Model 2420 are protected by a replaceable battery when power is
off. Typical battery life is approximately 10 years. The battery should be suspected if the instru-
ment 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 2420 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.)
Battery replacement precautions
WARNING
There is a danger of explosion if battery is incorrectly replaced. Replace
only with the same or equivalent type recommended by the manufacturer.
Dispose of used batteries according to federal, state, and local laws.
WARNING
The precautions below must be followed to avoid personal injury.
• Wear safety glasses or goggles when working with lithium batteries.
• Do not short the battery terminals together.
• Keep lithium batteries away from all liquids.
• Do not attempt to recharge lithium batteries.
• Observe proper polarity when inserting the battery in its holder.
• Do not incinerate or otherwise expose the battery to excessive heat (>60°C).
• Bulk quantities of lithium batteries should be disposed of as a hazardous
waste.
Table 4-4
Analog circuitry checks
Step
Item/component
Required condition
Remarks
1
2
3
4
5
6
7
8
9
TP200*
TP201*
TP202*
TP203*
TP213*
TP218**
TP219**
TP214**
TP232*
>60V voltage protection
10V
10V (SVMI)
10V
10V
OUTPUT COM
OUTPUT COM
SVMI, OUTPUT ON, 20V
Bench defaults
-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
Summary of Contents for SourceMeter 3A 2420
Page 2: ...Model 24203A SourceMeter Service Manual A G R E A T E R M E A S U R E O F C O N F I D E N C E...
Page 15: ...1 Performance Verification...
Page 31: ...2 Calibration...
Page 53: ...3 Routine Maintenance...
Page 56: ...3 4 Routine Maintenance...
Page 57: ...4 Troubleshooting...
Page 70: ...4 14 Troubleshooting...
Page 71: ...5 Disassembly...
Page 78: ...5 8 Disassembly...
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Page 84: ...6 Replaceable Parts...
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Page 107: ...A Specifications...
Page 112: ...A 6 Specifications...
Page 113: ...B Command Reference...
Page 124: ...B 12 Command Reference...
Page 125: ...C Calibration Programs...
