Wednesday, November 4, 2009

Soldering Iron Fix

While working on a SMT project, my finger was getting tired of holding the "heat" button on my new Soldering Iron. See previous post.

Sometimes the Iron would NOT heat up as fast as normal, and the work light would not be as bright.  Wiggling the switch would correct the problem, but a lot of pressure was necessary to hold it ON.

I had a similar problem before, and noticed then that the plastic button seemed to be melting on the inside at the point where it pushes on the copper spring switch.  When pressed, the copper spring is pushed down onto a screw head to make electrical contact. To help avoid the button from getting hot and melting, I place a small piece of heat tape over that area of the spring. I thought that was going to solve the problem - but NO. The  heat from the copper spring was being generated by the "bad contact" between it and the screw. And the added pressure needed was still making my finger tired and the strain would cause my hand to shake (a little) - which is not good for SMT work.

This had to be fixed!

I though, I may have to replace the switch with something with a more positive contact. Why did "they" make such a dumb switch for this thing?

I decided to take it apart and fix it, again. I could see where the contact seemed to be marred from heat, but what to do about it? What I need is something that would help make a better positive connection.

I found it - I placed a small drop of NOALOX - an Anti-Oxidant Joint Compound, on the head of the phillips screw, see the black dot at centre of photo.

Now the Soldering Iron works like a champ, I can still recommend the Iron, but suggest, fixing the switch contacts before use.

The back side point of my plastic switch button has been melted a little, but still acceptable, I may need to find a replacement.

Also, I think a small dot of NOALOX on the Tip wire holes will be beneficial, or at least that what I am trying.

OK, the implementation of switch is not dumb, it just had bad contacts.


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