Brother PR655 Service Manual page 219

Test mode Selecting test mode
#21. Serial numbers display
The stored serial numbers and product ID in EEPROM of the sewing
machine are displayed, and the installed program version in the sewing
machine is displayed at the bottom side.
The type of each component is displayed at the middle of the screen.
1 : PR650e/PR655
0 : PR650
#22. Switch checking
Check whether the [Start/Stop] button, [Thread trimming] button and the
[Automatic needle-threading] button are operating correctly.
The (color: red) is displayed under the switch name while pressing each
switch.
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