CLASS E1 Repair

[Donvito]

I have absolutely no confidence in my ability to solder my CLASS circuit board. Has anyone tried any cold methods of repair, conductive epoxy, conductive pens, etc?

[stanG]

Really all you need is a good soldering iron and some electronics solder. Go for it

[camos]

Really all you need is a good soldering iron and some electronics solder. Go for it

 

I tried unsuccessfully to repair my CLASS a few times using a $10 soldering iron. While the cheapo soldering iron would eventually get hot enough the heat was so dispersed that it would start to melt everything in the near vicinity. I bought a $60 soldering iron, which is about mid-range for price, and Bada-Boom it worked with no muss, no fuss. I felt like an expert.

 

Try it you will like it.

[Howard B]

If I can do it with my inexpensive tools and limited skills. then you should have no problem fixing it. Mine still works.

[dacheedah]

desoldering braid works well and flow on new solder, a decent iron is a huge help

[bongobobny]

Use a lower wattage iron specifically for PC board work...

[syscrusher]

Lower wattage FINE POINT soldering iron and a wet sponge that is NOT PLASTICS based. The old cheapo sponges that are hard and unbend-able until they are wet is a good choice.

 

One of the keys to soldering is to "tin" the tip, which means to just melt a little solder onto the tip of the iron. Work it around some so that you are assured that the entire tip has an affinity for the solder. Cleanliness is king. Wipe off the excess on the wet sponge BUT you need just a bit of molten solder on the tip to aid in heat conductivity. This is it then, dress or tin the tip and use that to conduct heat to the metal that you want to solder, BUT, apply the solder to the heated part when attempting a bond NOT to the soldering iron. Don't use too much solder, you are primarily just doing a remelt, but a little fresh stuff won't hurt. A remelt is the easiest soldering you can do really.

 

Now the important stuff, once you melt it remove the heat and then DON'T LET IT MOVE! Not a bit. If it wiggled around while it's cooling and rehardening you can create a crude diode junction called a "cold solder joint" that can be responsible for some intermittant failures. Actually it's fairly impossible to not move it at all and the materials are less difficult than I first stated but you need to be aware that you do need to make a good effort to avoid creating a weak joint which absolutely will happen if it moves a lot while cooling.

 

You should have some good magnifying glasses or other optical aid and be careful to heat only what you want soldered, work on only a single connection at a time unless all of the connections are on the same solder pad. Always heat the entire solder pad where multiple connections occur, you are trying to reflow the solder and each pad is a continuous joint except for where it is not, such as ground planes and power buses that may have multiple connections over a physically large area. These have multiple connections but are considered traces rather than pads and each connection would be considered separately except for where many connections converge together.

 

Got it? Go get it.

[Donvito]

Thanks to all for the advice. You've convinced me that soldering is the way to go. Just afraid of destroying an irreplaceable component.

[Flyinfool]

For board repair I like to use some flux and a silver bearing solder. The lead solder cracked once already and the silver bearing solder is both stronger and more conductive.

For your soldering pencil, I would recommend the 40W for the bigger terminal solder joints or soldering bigger wires together, and a 15 / 30W for component leads.

 

DO NOT use plumbing solder because it has an acid flux that will eat electronics. Also do not use acid flux for the same reasons. ONLY rosin core solder and rosin flux. Since you are not experienced with soldering, you do not want to mess with the modern lead free solders, they are harder to work with. You want solder with lead in it. Just don't eat it and you will be fine unless you live in California.

 

A Radio Shack shopping list to get you started

 

Rosin Flux P/N 64-022

Silver Solder P/N 64-013

40W Soldering Pencil P/N 64-2071

15/30W Soldering Pencil P/N 64-2055

[Wizard765]

Thanks to all for the advice. You've convinced me that soldering is the way to go. Just afraid of destroying an irreplaceable component.

 

 

I know it would be an expense but if you want to ship it to me I'll do it for you..

[Flyinfool]

I'll bet that you could find someone local to do it for Pizza and/or Ice Cream. Some might even travel quite a distance for a "free" meal.

After all we seem to be an eating club with a riding disorder.....

[Donvito]

Thanks to all for the advice and offers. I found out my brother has experience with repairing electronics and has the tools. He has offered to do it for me.

[bongobobny]

Yay!!!!!!