hairdryer on electronics

[tony359]

Potential silly question for the community.

I often use hot air to diagnose components, as they often revive/die with heat/cold. I use my hot air station and freeze spray.

I was asked whether I could use a hairdryer to warm up PCBs. Obviously you won't have the ability to direct the heat to a specific component but what about ESD? Is it safe to use a hairdryer on an electronic board?

Thanks!

[CapLeaker]

It’s like watering a garden with a fire hose. Possible, yes. A good way of doing it? Probably not.

[petehall347]

never heard of it causing a problem .

[redwire]

Violent airflow through a plastic hose or nozzle or across a PCB will generate a static charge. It's miniscule- but not the case if it is charging up something big as a capacitor and there is no leakage path. Like a person.
This was known a long time ago with techs vacuum cleaning or using compressed air to clean equipment, there were ESD-related failures. Then 3M came out with special vacs using dissipative plastics.

If you don't touch (discharge) the nozzle/hose to yourself or the gear I think it's not a problem on an ESD mat, and stay grounded.

You can also watch a multimeter DCV reading with air blowing across one probe in contact with large metal - PC board etc., other probe earth-grounded. As a primitive electrometer.

[CapLeaker]

Personally I use both and never had any trouble. But then I don’t use the hair dryer to fault find as such on a naked board. The nozzle is just to big to fault find anything with. I just use it to warm something up maybe or to get a PSU going in a pinch if the starter cap has failed.
My Weller hot air is running circles around a hair dryer for fault finding.

[tony359]

Thank you!

Yes, it's not the best way but I have been asked if I would recommend it for a wider audience, that might not have a hot air station. I just wanted to make sure I wasn't going to recommend bad things, that's all! The purpose of the hairdryer is just a quick a dirty way to see if the board starts working again when warmed up.

Thank you all!

[CapLeaker]

It’s like watering a garden with a fire hose. Possible, yes. A good way of doing it? Probably not.

[VoicesFYC]

the Official Answer ... is YES...You Can and sometimes with a varable temp hairdryer you can find the temp issue faster Daniel.

[PeteS in CA]

The problem with a heat gun or hair dryer and with freeze spray is that it affects a large area. With freeze spray I soak the tip of a cotton swab with it and then touch the suspect component with the cotton swab tip. Doing something similar with a heat gun is a bit more difficult, and if your probe is metallic, you need to avoid shorting to something.

[tony359]

I use the plastic tube of my air dust can (used upside down). With that I can precisely freeze one component if I gently press on the trigger and prevent splashing all around.

See my own video here: https://youtu.be/AL64ADVLlJc?t=740 (it should take you to where I freeze a tantalum cap).

Heat gun or hairdryer is difficult of course.