27
That $15 flux pen I bought from Amazon nearly ruined a whole board
I was working on a old Denon receiver last week, had a cold joint on the HDMI input. Grabbed this no-name flux pen I'd picked up for cheap, went to town reflowing. Board looked fine, powered it up, and it started acting crazy - random shutdowns, audio cutting out. Turns out that flux pen was some kind of acidic garbage that started eating away at the solder mask after a few hours. Had to scrub the whole area with isopropyl and redo all my work. Lesson learned - cheap flux is not worth the risk. Anyone else get burned by bad flux or am I just unlucky?
2 comments
Log in to join the discussion
Log In2 Comments
oscar_ellis1mo ago
Buddy of mine had the same thing happen with a cheap pen, ruined his whole weekend.
3
lunakim1mo ago
Are you sure it wasn't something else going on with that board? Old Denon receivers have a bunch of common issues, and cheap flux alone turning your solder mask into a mess in just a few hours sounds pretty extreme. I've used those no-name flux pens from Amazon on plenty of scrap boards and never had anything melt or eat away like that. More likely that receiver already had something corroded or cracked from years of heat cycles, and the reflow just stirred it up or made it worse. You sure it wasn't a bad cap or a loose connector making that board act crazy?
3