A Mouser BOM is forming around the TDS 520. Found all the RIFAS. Some of the SMD caps have greasy circles around them, so leakage is apparent. I'm pondering removal methods;
- Solder tweezers. Not a thing I've got, and I'd need to get a full station to drive them. Limited usage beyond recapping SMD.
- Hot air. Also would need to go on the shopping list. Can literally cost anything. But capable of doing more.
- The Carlson trick of cutting the Al part off the seat, and then going down towards the board. I've got all I need for this. And, it does not look as crazy "rip'em off like they wanna experience pain" as it's sometimes described. (trick apparently is to cut of the bucket first, and then work down until there's only easily (individually) desoldered legs left on the pads.)
This, also, is not investment season. Vacation was impressingly expensive, and everything else is too.
I prefer to do them with "dual wielding" soldering irons, but sure, the more they have leaked the harder it is because the solder wont easily melt.
But that also makes it more vulnerable to the "Carlson method" so it's a bit of pick your poison...
Didn't see this earlier. Some points:
1. solder tweezers. Can emulate this with dual irons. You can fix the solder melting problems with a flux pen. That kills enough oxidation to get down to the pads.
2. Hot air. Do not do this with SMD electrolytics. They can explode if you get them too hot.
3. Don't even get me started on the Carlsson method. You're dealing with potentially damaged pads through oxidation so mechanical pressure on them may rip them off the board. This method was actually recommended a long time ago on certain components which seems to have been brought into the future somehow. It was a bad idea then too and was relegated to service technicians.
Generally the idea is that if you can't imagine NASA doing it, probably a good idea to avoid it.
My comment earlier to mansaxel in the Discord was that "If I had a mainboard from a precious that was full of SMD electrolytics, I wouldn't touch it without hot tweezers."
The reason being twofold:
1) A
lot of them usually means high component density. This makes it much more likely that you'll fuck up a few times using the "dual wield" method. It only takes once in the wrong spot to ruin such a PCB BER.
2) A lot of them using dual-wield is just fucking exhausting... that makes it likelier you'll fuck up too. Hot tweezers turns a job that's a "charlie-foxtrot waiting to happen" into "Meh... just sweeping the floor" tedium. Much less likely to fuck up a Unobtanium board you care aboot.
Trying to dual-wield large numbers of SMD electrolytics is a horrible, half-assed way to do it.
It is, to quote Saruman the White, "...the way of
pain!!!"
My 4 bits worth; take from it what you will.
mnem