Picked up a tip about cold solder joints from a retired TV repair guy

He told me to always hit suspect joints with freeze spray before testing. I tried it on a power supply board that was acting flaky and found two cracked joints I'd missed with my microscope. Has anyone else used that trick for intermittent faults?

2 comments

2 Comments

hayden_rivera16d ago

My cheap freeze spray can is the only tool in my box that's dumber than me.

jessec3916d ago

That freeze spray thing reminds me of something an old radio guy told me once about tapping components with a wooden stick while the board was running. He said the wood wouldn't short anything out and you could hear the bad solder joints crackle or pop when you tapped them. I tried it on a monitor that would lose vertical deflection after warming up for like 20 minutes. Tapped around the flyback transformer area and found a resistor that had one leg that was completely loose but looked fine visually because the solder had just cracked under the component. The weird part is that I had checked all those joints under magnification already and they looked solid. Something about how the heat cycles make the cracks open up only when the board is hot I guess. That freeze spray trick is probably doing the same thing but in reverse by making the metal contract and exposing the bad connection.