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Hi to all,
I experienced the same problem a few years ago when RoHs became mandatory.
did some research & found an explanation.
Essentially, have two complete separate sets of soldering/desoldering tools.
One for RoHs, one for traditional rosin-core work.
The explanation given was that even minute quantity mixing of the two types of solder gives what was called "an eutectic mix of metals" and was found to not even melt well at 515°Celsius (guaranteed destruction of PCB traces).
Even just a "wetted" soldering iron tip is enough to provoke the problem.
The chap who wrote the article solved it this way :
- on RohS soldered circuits, used RoHs iron to desolder.
- cleaned component pads/holes extremely thoroughly
- mounted new components using rosin-core with other iron
I experienced exactly the same problem as ReeferMan while trying to replace 6 x through-hole electrolytics on a vintage NetGear DSL modem.
All i got was clobs of un-meltable mixed solder lumps, whatever the tip temperature. Did some searching to understand why.
i hate RoHs ! lumpy/grainy aspects & heightened long term risks of bad contacts.
Best Regards
jhalphen
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