On Thursday, April 11, 2013 9:12:39 PM UTC-4, Jeff Liebermann wrote:
On Thu, 11 Apr 2013 15:19:43 -0700 (PDT),

wrote:



I have a Hougen Magnetic Drill that is not working.

http://i290.photobucket.com/albums/l...pse1f7add1.jpg

(...)

Would it be plausible to re-flow the solder on the circuit board in case there is a cold solder joint somewhere?



Yes. Take a photograph of the various plugs so that you can put it

back together correctly. Unplug everything. Wiggle the connectors

and you'll probably find the "cold" solder joint. Reflow the solder

connections using the same type of solder that was originally used

(Lead-Tin or RoHS type). Clean off the flux. If you try to solder it

with the connectors plugged in, you'll either solder the connectors

together, or melt the plastic insulators. Also, look for "insulation

crimps" on the wire plug ends.



However, I don't think that's the problem. My crystal ball suggests

that the brushes on the motor may be the culprit. Try using your ohms

guesser on the brush contacts and see if the motor presents a few

ohms. Also spin the drive shaft to see if you don't have an "flat

spots" on the commutator. Of course, visually inspect the brushes.



If that looks ok, it's probably something between the power and the

drill motor, which is infested with interlock switches. Each should

be checked individually with the ohms guesser for continuity.



Incidentally, I failed to find a schematic or wiring diagram online.



--

Jeff Liebermann

150 Felker St #D http://www.LearnByDestroying.com

Santa Cruz CA 95060 http://802.11junk.com

Skype: JeffLiebermann AE6KS 831-336-2558

Here are the Manuals for my model:
http://www.hougen.com/downloads/10904.pdf
http://www.hougen.com/downloads/misc...structions.pdf
http://www.hougen.com/downloads/misc...aded_spind.pdf

After taking out the screws I couldn't figure out how to separate the motor housing from the slide. (I tried using a rubber mallet to knock it loose). But I unscrewed the top plate and saw where the brushes were located and then got to them by unscrewing the small circular plastic covers at opposite sides near the top of the drill housing.

http://i290.photobucket.com/albums/l...ps466ba0d6.jpg

How do I know they are still good? (The rectangular brushes are about 1/2" x 5/8" x 3/16").

Anyway, I put the drill back together and while progressively manipulating the safety switch adjustment between power up tries I got to the point where the drill would turn on, which it wouldn't do before.

So I'm still at a loss as to what the problem was. I probably didn't re-insert the brushes *exactly* the way I took them out and was wondering if that might be the reason it is working now.

What other procedures should I undertake before I start re-flowing solder on the control PCB? (Since I have to sell the drill I want to be sure it is working properly). Can anyone tell me where I can find new brushes?

Thanks a lot.

Darren Harris
Staten Island, New York.