Brother MFC990CW Service Manual page 528

[ 2 ] Unplugging the power cord from the electrical outlet and disconnecting the
backup battery*
*
For models with backup battery
Unplugging the power cord from the electrical outlet and disconnecting the backup battery*
deletes the Caller ID list, fax data received into memory, transmission verification report (for
image), broadcasting report and batch transmission data (in the memory).
Operating Procedure
(1) Unplug the power cord from the electrical outlet.
(2) For models with backup battery, disconnect the battery harness from the main PCB. (see
Chapter 6.)
(3) Leave the machine for approx. 24 hours.
Confidential
App. 7-2