I've just using my heat gun on a atx motherboard
Hi.
Now I have some experience of using a 2000W (package claim 300/600 degrees celsius) Cotech heatgun, and I will try to share the experience as good as I can here.
First of all, Don't try to do this in your house where you live. You think that the smell of a regular solder iron is bad? Using a heat gun probably produces at least ten times more smell.
The advantages compared to a little solder gun should be obvious. I can tell from my experience the cons and pros.
Pros
* You'r able to get components and contact with a large number of pins off the printboard.
* 2000W is really an overkill when the job is to get out one single cap that fill the repair need of another computer, but it gets the job done.
* The component legs is often more clean - the small tubes that connect the paths within different layers stays in the wholes. This have previous being a problem when using a solder iron on components with multiple pins.
* It's really easy to pill off smd components too - just heat the spot on the oposite side on the print board.
* If the goal is to pill off all solded components on a mainboard, it's far more efficient than using a solder iron.
Cons
- If used to pilling off smd components, the nearby paths often get loose before the component itself. So that effectly kills a print board.
- Nearby components is likely to fall off, since the heat gun cannot heat just a little spot on the printboard.
- Cannot avoid grilling nearby plastic parts - wich gives a really bad smell.
- Giving the above cons, a heat gun cannot be used to "fix" a printboard.
I'll also tell about my experience about the different types of components and their ability to survive.
Caps
I haven't tested the caps to see it they work so I cannot really tell at this time. Ill I know for sure is that they got loose without any particular problems.
I beleive most of the caps did survive because the rate of the heat should be more gentle than for a solder iron, as both legs are heated up simultaneous and it takes more time for the solder tin to melt.
Inductors
Nothing to tell. Just be careful with the polygrip tool and avoid damage to the winding insulation. Since two legs is heating up almost simoustanely a flat screwdriver can be used to pill the inductor off the board.
I guess the same can be said about resistors, but the motherboard didn't had any regular resistors.
BCD led display
To be onest, I thaught that it wouldn't work and the housing would melt and get loose. But, it did work and the display looks like coming straight from the production line. Success.
Main power connector (made of plastic)
This was one of the thing I just HAD to try, even if I was almost sure that the plastic housing would melt and that it would be just a mess of melted plastic and baked-in pins.
But, it turns out to work as the plastic house around the atx pins actually survived the temperature. Not only did it survive, but the plastic house is not deformed at all. I probably had my luck here as all of the pins came loose pretty fast. If one or more pins refused to get loose the plastic housing would probably not survived and get deformed.
Big connectors such as stereo jack outputs and usb/nic housing
Worked lie a charm. But, it takes much more heat to get a big connector loose than a single cap. Espechially as the casing metal is conducting heat wery efficient. Because of the need to use of exessive heat, nearby components as caps, inductors etc will fall off before the connector.
USB connector
This is the only connector that does NOT survive the heat as it is used another type of plastic that doesn't stand the heat.
Fan connector (3 pins)
This connector introduce a new problem. The polygrip tool will often have a good grip on two pins, but not the third. As a result, only two pins get loose while the last one is still stucked to the printboard. Holding the polygrip very tight will solve this in most cases.
Another thing I had to test while I was outdoor with heatgun and mobo. Some of the inductor with external housing was close to the cpu socket where the back side of the printboard was covered by plastic foam (or what it is called).
Exept from a lot of bad smell from melted plastic I got the inductors loose without any problems.