Fixing my Wahl 9918 Groomsman Beard and Mustache Trimmer

Not everyone would bother repairing a $25 beard trimmer, but why not fix something for under $5 instead of spending another $25?

My Wahl 9918 Groomsman Beard and Mustache Trimmer has admirably performed its beauty duty for many years, but the time came when the battery just wasn't holding a charge any more.  Most people would just put the trimmer in the trash and buy a new one, but I figured I could repair my otherwise excellent Wahl and save some money.

In fact, even high priced trimmer and rotary shaver brands, like Norelco and Remington, can be easily repaired using a process similar to the one I used to fix my Wahl.  Read on to find out how.

I opened up the Wahl by popping off the black plastic faceplate with a tiny flathead screwdriver, which revealed two screws.  By removing the two screws I was able to easily open up the unit, revealing the guts of the device.

Backplate off, Revealing the screws

The internals are rather simple: a motor, a simple circuit board, a switch, and a NiCad battery pack soldered into place.

The Internals, with new battery pack

I concluded that the battery was no longer holding a charge, so I worked to replace it.  I bought a set of NiCd Rechargeable AA Cells with Solder Tabs.  The solder tabs are very useful - they make it reasonably easy to solder together a new battery pack.   You can also buy pre-assembled packs to repair Wahl, Norelco and Remington products with, for example, the battery packs found here.

To create a new battery pack using two cells, I used some electrical tape to wrap together the two new cells, in plus-to-minus orientation.  Then I used a trusty soldering iron to solder one of the plus/minus tabs together.  I pulled the foam off the old battery pack and stuck it onto my homemade pack.

Then I unsoldered the old battery pack from the Wahl and soldered my new pack in its place, ensuring that I kept proper polarity.

After, I cleaned up some corrosion on the switch with a pencil eraser and an emery board, and reassembled.  A little test proved good, and so I plugged in the trimmer and let it charge overnight.

Now the Wahl works like new! It runs perfectly and charges perfectly to.  It continues to provide me with a beautiful beard, 15+ years running.

UPDATE, 2019-07-06

In my haste to trim my beard, I dropped my beloved Groomsman onto the bathroom floor resulting in the cutting head detaching from the body.  The plastic mounting posts of my Groomsman had cracked, leading to loose screws.  The cutting head would not say attached to the body.  Ug!

I was planning to resign and buy a new Groomsman, like this one.  After all, the cracked part of my Groomsman is normally under a significant amount of stress, squeezing down on the spring system of the cutting head.  It seemed like a plastic structural repair would not be reliable.

But I love the Groomsman that I've owned for so many years.  I decided that it would be worth trying to repair the cracked plastic posts with that super standby, cyanoacrylate adhesive (super glue).

I cleaned the broken plastic with rubbing alcohol and let it dry.  Then I used small dots of liquid super glue (not the gel kind) on the broken plastic parts and held it all tightly together with some tape and rubber bands.  I let the adhesive cure for a full 48 hours in a humid environment (that's how super glue cures!  Humidity!). Then I carefully reassembled my Groomsman by mounting the head back on the body with the two mounting screws.

The result? Excellent! My Groomsman lives on, for a mere 10¢ worth of epoxy.

Don't give up!  Keep your Groomsman grooming.