Heard a radio repair guy swear by the freezer trick for finding bad capacitors yesterday

Was at a flea market in Phoenix last weekend and this older fella was telling his buddy about it. Said he sprays a can of compressed air upside down to get it cold, touches each cap, and the bad one drops voltage when it freezes. Tried it on a monitor I been fighting with for like 3 weeks. Found a 1000uF cap that was showing good on my meter but dropped to like 2V after 10 seconds of cold. Replaced it and bam, fixed. Anyone else use this or got a better way to find those intermittent ones?

3 comments

3 Comments

john6501mo ago

So you're saying spraying coolant on a cap is the same as actually measuring it... I don't buy it. Temperature changes mess with everything in a circuit, not just the capacitor you think is bad. You could be chasing a ghost while the real problem is a cracked solder joint or a resistor that drifts when it warms up. And inverted air leaves that nasty residue sometimes, you're just asking for more trouble later. Seems like a party trick for guys who don't own a proper ESR meter.

cole9941mo ago

Ngl you kinda changed my mind there.

theac631mo ago

Hold up, so you're saying you've never had a flaky cap that passed an ESR test cold but showed its true colors under heat? I've had plenty of old motherboard caps that tested fine at room temp but dropped voltage like crazy after the system ran for 20 minutes. A quick freeze spray pinpointed it way faster than desoldering and metering every single one. Not saying it replaces an ESR meter, just that it's a decent diagnostic trick when you're already in there.