Repair Palson Revolution Hair Clipper

Once every two or three years in the life of a hair trimmer, you come face to face with reality: batteries wear out. A lot. Suddenly they don't last the whole cut, they charge suspiciously fast... it's not like it used to be. In this instructable I show you how I changed the NiMH rechargeable batteries in my shaver.

To see the video of the complete process, check out the video in my channnel: https://youtu.be/1th9I-Ep2-0

Phillips screwdriver, tin soldering iron (with tin), 2 x AA NiMH rechargeable batteries, IPA -isopropilic alcohol- (optional), pliers, multimeter (optional).

Lifts the blades of the hair clipper by pressure.

Unscrew the screws: 1 at the rear and the two under the blades.

Open the hair clipper from the front (where the button is) and remove the cover.

The pcb must be cleared to desolder and re-solder the new batteries by:

a) detaching the motor from the housing: remove the screwed metal clip,

b) removing the motor and the pcb: it is press-fitted (the batteries are under the pcb)

c) desoldering the motor from the pcb and

d) desoldering the connections to the rear load (the vertical load). Beware that the soldered points to be detached are the exterior ones (see the images) of the 4 connections located in the bottom part of the hair trimmer. The interior two are the ones for the cable connection, do not touch those.

Change the batteries:

a) detach the worn out batteries: you can do it with the pliers or by hand, like me, with an oscillating movement. I recommend my way because more connection strip is conserved this way. WARNING, the element that can be seen between the batteries, attached to the pcb, is a Thermistor, a protection feature used in the charging process of the batteries. Be extremely cautious with it, don't damage or move it.

b) join the two new batteries next to each other, ready to be connected in series and respecting the pcb polarities (see the remarked image), i used duct tape.

c) tin the four terminals of the batteries. WARNING, the heat must not exceed 5/10 seconds in each terminal in order not to damage the batteries. To prevent overheating, use rosin to speed up the soldering.

d) connect the bottom terminals of the batteries with a wire (tin also the two terminals of the wire)

e) tin the conserved connection strips of the pcb

f) solder the connection terminals of the batteries to the connection strips of the pcb.

Just reattach everything the same way it was. You can clean up the rosin from the pcb with IPA if you want it to be more cosy. Use a cotton swab for the job.

Remember to attach correctly the 5521 connector (the connector to the charging cable) -see images-, check that it is well connected by connecting the charger before continuing the reattaching.

And there you have! Enjoy your new hair trimmer!