Keithley 2700, Service Manual

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3-8 Routine Maintenance
Replacing non-volatile RAM battery
The Model 2700 has a three year battery for non-volatile RAM. Use the procedure below to
replace the battery, if required. Refer to the disassembly procedures in Section 5 and the parts
list and component layout drawings at the end of Section 6 for more information.
WARNING The following procedure is intended only for qualified service personnel.
Do not perform this procedure unless you are qualified to do so.
Disconnect the line cord and all connecting wires from the Model 2700
before removing the top cover.
1. Before replacing the battery, refer to the troubleshooting procedures in Table 4-4 in
Section 4 to determine if the battery requires replacement
2. Remove the Model 2700 top cover using the disassembly procedures in Section 5.
3. Locate battery BT100 using the motherboard component layout drawing at the end of
Section 6.
4. De-solder the battery from the top side of the circuit board.
5. Install a new battery, Keithley part number BA-51, taking care to observe proper
polarity.
6. Solder the battery connection to the circuit board using organic (OA-based) flux solder.
7. After soldering, remove all flux using a foam-tipped swab or brush dipped in pure
water. Blow dry the board with dry nitrogen gas, then allow the board to dry for several
hours in a 50˚C, low-humidity environment before use.
8. Re-install the top cover by following the disassembly procedures in Section 5 in reverse
order.