EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: Osirus on September 09, 2020, 10:51:36 pm
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I have to replace a couple of bad transistors on this board. The Base pin came out just fine with a solder sucker, but the Emitter and Collector pins are in these eyelet things that appear to be on both sides of the board and I cannot get them out. I had to cut the leads to remove the transistors, but still can't get the leads out. I'm not even sure what they are or what their construction is like.
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They're rivets for extra structural integrity of heavier components. Not unusual on some single side through hole PCBs . How many watts is your soldering iron because 60W irons have some difficulty with these but not impossible.
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I have a WES51 and had it at 700F. Should I be able to remove them by heating the pads underneath while pulling the leads from the top?
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Just be careful not to over heat the traces. The epoxy doesn't like very hot temperatures for extended periods of time and the traces may lift from the board. I use a 250W Weller soldering gun for things like this if the 120W station won't do it. You can cut the wire flush and drill out the solder as well .
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Cranked the heat all the way up and got them pulled out. Thanks!
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You would probably need hot air + soldering iron simultaneously
Old technology iron are not good for big thermal mass.
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One trick is to add solder.
Not much, but just a little bit between your soldering iron and whatever you want to desolder.
The goal is to improve the contact between the soldering iron and your object for better heat transfer.
Using thicker tips int the iron also helps in this regard.