One of the brothers in my campus ministry offered to cut my hair this weekend, except it had one catch: their Conair hair clipper wasn’t working! A few hours later I had the rogue clipper in my hands and proceeded to take apart the case to peer at what was inside. Seeing no burn marks from the infamous black smoke inside, I checked the battery voltage and was surprised to find it put out a measly .26V (it was a 3-cell Nickel-Metal-Hydride). I was a bit disgusted at this, as it appeared that one of my first real electronics repair jobs was a major failure! However, the next morning one of the other brothers let me borrow his Conair clippers, which happened to be a similar make and model, and also cordless. When we plugged that one in, it took about 3 seconds for the slowly whirring blades to speed up to a decent cutting speed. Almost instantly I had a guess at what could be the problem.
ECE majors: STOP! This one’s for you! Think about the problem, and see if you come up with the same conclusion that I did below! :)
So, what was the fix? Basically, the clippers were designed to charge the battery which in turn would power the motor drive for the clippers. When the batteries start dying (in this case, under a year or two), you are unable to use the clippers unless you get a new battery or pay shipping and handling to Conair for their 5-year-warranty (on a $20-$30 clipper set). The fix is to simply desolder the battery from the circuit board, causing it to work just like a wired clipper should! Now, I’m not sure if they did this on purpose, but it clearly is a poor way to go about getting repeat customers for your products. I hope they fix this in future versions of the product, and if not always buy a wired clipper!
NOTE: On the newer clipper, it has some sort of auto-adjust “SMART” feature for automatically some more power to the motor. This caused the clippers to turn on temporarily and then turn off again right away when I tried turning it on. I believe this is from some sort of current limiter on the chip inside, and the only way I could fix it was by flicking the power switch up and down a few times and trying to hold my fingers on the blades to stop it from moving, sort of conditioning it with a higher load than it normally runs at. Once you get it working, it should work normally if you keep it running.
Attached are some glamour shots of the circuit board (I de-soldered the B+ and B- wires and heat-shrinked it for good measure) and of the really cool motor assembly that generates the back and forth motion (a rod offset from the axis of the motor). Hope this helps, and leave any questions you have in the comments!
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- The Conair Clippers
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- Conair Clipper 1
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- Conair Clipper 1 Closeup
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- Conair Clipper 2 Closeup
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- Motor Closeup
what would have the heat-shrinking done that would have affected anything?
It’s mainly a cleanliness thing. Having exposed wires in general isn’t a good thing to have, although in this case it probably wouldn’t do anything bad to the battery.
Can you tell me how to repair this Conair board? It is slightly different from yours. I tried to draw in the batteries. Please disregard the black wire behind that
http://img35.imageshack.us/img35/7382/img2617modified.jpg
Hi Joe! What I did was remove the batteries entirely from the circuit. My clipper still worked as the motor and batteries were hooked up in parallel. It should be the same case with you, just unhook B+ and B-. I don’t see / can’t figure out where B- is on your board, but I do see a B+.
Let me know what you find!
Hi nolan, the B- is hidden. I think the battery isn’t in parallel here:
http://img713.imageshack.us/img713/7382/img2617modified.jpg
I think even without the battery, the clippers did not work
Hmm, okay. Your board looks pretty simple, so I’m surprised it’s causing this much trouble! Could you maybe take a picture of the back of the board (especially if there are any components on the back). If there is no voltage regulator on the back, you should be able to take the risk and wire the input power straight to the motor with limited consequences.
hey Nolan, I have a conair HC318R. I dropped it earlier while i was using it and the blade popped out. The smaller blade and the two white plastic pieces including the metal spring came apart as well. I was wondering if you can post a pic of the blade so I can see how I can put it back together. Thanks.
http://imageshack.us/photo/my-images/24/bladespic.jpg/
Uploaded with ImageShack.us
Hey Eric! I uploaded a new photo that has my assembly. It looks slightly different and lacks the pastic piece on the blade, but hopefully it helps. I don’t see any plastic parts that are sheared off, so you might have a chance at putting it back together again. Good luck!
Hey, thanks man, the pic was a great help. I was able to see how everything fit together and was able to fix my clipper. Thanks again!
w00t! Awesome
Pic #6 was the one I needed! Thanks Nolan!
Hello,
Did anyone think of just going down to a store and buy new battery’s? Ni-cd 3.6 900mAh are availible from many electronic stores (Harbor tools) in california are where I got mine. Anyways take out the old battery pack, take notice on how the battery’s are wired (un-solder the red wire) also at the ends of the battery’s you’ll see that the battery’s are connected a certain way with each other. Just repeat it with the new batterys. Tape all 3 together & use black cushion from old like original and put back in. Make sure to re-charge fully before using. Best to also run batterys all the way down before re-charging to make them last.