Replace the motor in the Bosch PSR 10.8 LI-2 cordless screwdriver

ID: 180344

Description: The Bosch PSR 10.8 LI-2 cordless screwdriver is...

Turn off the cordless screwdriver (remove your finger from the trigger).
Remove any tools from the drill chuck (screwdriver bit, bit holder, drill bit).
Remove the battery from the handle, if present.
Have a Torx TR8 screwdriver and a sturdy lever (e.g., any flathead screwdriver) ready.

Remove the metal clip at the bottom of the handle (where the battery is inserted) that holds the two halves of the housing together. The best way to do this is to pry it out with a standard screwdriver.
Place the metal clip with the housing screws.

Carefully remove the right half of the cordless screwdriver's enclosure and set it aside.
Be careful, as the red sliders (speed selector switch, forward/reverse switch) or the transparent plastic parts (light, forward/reverse indicator) may come loose. Set these aside as well.

Carefully remove the upper red gear selector and set it aside. It has a metal spring on the drive side that is loosely hooked into the gearbox.
Next, lift the front of the gearbox slightly and gently pull it away from the motor.
Now remove the drive motor as a whole, along with the motor controller (red connector, black battery connection, large circuit board), the operation indicator (small circuit board), and the wiring. Here, too, loose plastic parts (operation selector switch, lighting) may come loose.

The specifications of the old motor (old, still-connected) drive motor are located on the back.
Comp[ate these with the specifications of the replacement motor. In the case of the genuine Bosch replacement part, they differ only in the serial number.

Remove the old motor from the control unit by unsoldering the red and black wires, then replace it by soldering both wires to the new motor.
Make sure to solder the red wire (positive) to the terminal with a small red dot next to it. The negative terminal for the black wire has no marking.
The ribbon cable for the power indicator should be bent slightly to the side so that it does not get in the way during the soldering process and become damaged.
Any standard soldering iron or soldering station (e.g., T100) can be used for soldering. The soldering tip (e.g., D24) should be selected to be sufficiently large to deliver enough heat to the soldering point.

Place the motor into the left half of the enclosure. Make sure the cable for the power indicator runs underneath it and that the indicator is inserted into the recesses at the top of the enclosure.
Insert the motor control board into the corresponding slots. Make sure the cables to the motor (red & black) run between the board and the housing.
Press the black battery connector back into the corresponding slots.
Slide the gearbox and drill chuck onto the motor’s gear. If necessary, turn it slightly so that the gears engage and the gearbox fits snugly against the motor. Turn the gearbox so that the metal spring is on top
Insert the red gear selector at the top, making sure that the gearbox’s metal spring engages in the lower recess of the gear selector. The red operation selector must be placed on the tab of the motor control board.
Check that all moving parts are in the correct positions and functioning properly. The fixed parts (e.g. the lighting cover) must sit flush in their places.
Finally, place the right half of the enclosure on top and carefully press both halves together until they fit snugly and sit flush.

Finally, insert the metal clip into the handle and press it in firmly.
Then insert the 8 Torx screws and tighten them until they are “hand-tight.”
Insert the battery.
Test the cordless screwdriver: the motor should run smoothly without sparks or smoke (“give it some gas”). Also test the mechanical functions and controls: clockwise/counterclockwise rotation and forward/reverse, 1st and 2nd gear.

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