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Join Date: May 2011
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      05-14-2011, 08:13 AM
I am working on a project to replace some bad caps in my TV. While removing one of the caps, the lead broke in the pcb. I tried to get it out by:

- Adding more solder to try and liqufy what was left in the hole
- Heating and pushing\pulling

Ultimately, the lead is now to the point where it is flush with the pcb, and I can't get the solder to melt enough to push it through. The back side has been overheated...hopefully it looks worse in the picture than it really is.

Is it possible to just clip the lead of the new replacement capacitor to length, and solder it to what is left in the hole? I will have to of couse secure so it doesn't break in the future.

I could drill it out, but I'm not sure on how to repair the hole if it gets worse. The cap is a 470u 35v.

Thanks in advance for any advice.
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Broken lead-top.jpg   Broken lead-bottom.jpg  
 
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      05-14-2011, 03:45 PM
You need more heat from the iron, it's the only viable solution. The track seems to have survived the abuse btw..
The capacitor leads needs to be short for the high-frequency decoupling properties to be effective. I'd hesitate to use that solution.
If you can't get your hands on a better iron I'd try to insulate the one you have with fibre-glass cloth or something similar to raise its temperature.
Drilling it out with the lead in place will only result in a broken through-plating; don't do it.
 

Last edited by Resqueline; 05-14-2011 at 03:48 PM..
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      05-14-2011, 03:52 PM
There isn't much near the bad lead....will more heat damage the pcb or the connection itself? I will have to keep the iron on the lead for a while to get it heated enough. I was trying to be careful to not damage anything else.

The iron I have is a 30 watt pencil from Radio Shack. (Found a 40 watt Weller after I bought this one....bleh).
 

Last edited by Rikketyrik; 05-14-2011 at 04:08 PM..
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      05-14-2011, 06:27 PM
Damage is a function of time & temperature. A too low temperature (resulting from too low power or mass) results in too long time used, possibly resulting in damage.
A too high temperature can also lead to damage both due to the temperature itself and the difficulty of finishing the job in the "half of a second" required at that temp.
I used a 30W pencil for decades and could do most jobs with it. I noticed a difference when putting a long tip on it though; the increased area gave a lower temperature.
If you also put a short & thick copper tip on it could be better able to heat the area sufficiently quickly. Sufficient mass & temperature can compensate for low power.
 
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      05-14-2011, 08:35 PM
Was able to finally get it....bought a nicer soldering iron with a sharper tip to it. (returned the radio shack pencil). Using the newer tip, I was able to push it through....took a while though.
 
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