[CLOSED] Problem with IMU?

[tobias]

This video is pretty informative though it uses hot air station and solders the chip from beginning. Reflowing it is a lot easier.

[Call_me_a_Cab]

As a warning to anyone who wants to try this:

I just melted my crazyflie.

I used a 300 degree heat gun on high air setting, wrapped the fly in tin foil, lay some industrial heat insulation cloth over the top with a hole to the chip. I warmed the board and the focused on the chip while looking through a glass, after about 10 secs I thought I saw the solder start to shine, touched the chip with tweasers and though I seen it move a small amount. I though GET IN! Ive Done it!!

I turned off the heat, and watched as the board cooled, Then I saw the smoke.... I quickly struggled to unwrap the hot package but when I did the expansion ports had both melted, 3 of the LEDs had came off along with two other small components and the battery wires.

To anyone who tries this:

Be very conservative with heat! Be very conservative with time, probably 5 seconds would have done in my case. I would lay the foil over the top, do not wrap it! Remove the foil as soon as you are done.

Good luck and thanks to an awesome community and an awesome product for what little success I had with it.

[tobias]

Nooo, what a pity! I feel bad since I suggested it. Please check your PM.

I guess the temperature of the heat gun is pretty unpredictable and it must have been much more then 300 degree C to melt everything that fast. It seems like you managed to reflow the whole board in 10 sec, that is a bit faster the recommended...

Even though this seems to be pretty risky I'll try to do it myself and see if I can find an easy and "safe" method. There are others that it could help as well.

[tobias]

I'm also curious, have you tried the board? It sounds like no critical components has "broken" so you should be able to connect to it and see if the sensor problem is fixed.

[Call_me_a_Cab]

I was really surprised at how fast it happened too!

I would recommend de soldering the expansion connectors before doing this. I think my fatal error was "wrapping" the board instead of just placing the foil like a shield. I think that the foil contained a lot of heat and most of the damage happened after I stopped the heat gun.

I tried to connect but the mini usb plug wont fit properly any more and some of the resistors moved when I unwrapped the still hot package. Looking at it, I may be able to get them back into place using the gun again or maybe an iron. I will post a photo later and you can see if you think it's doable.

On the bottom side 3 of the motor connectors melted too and some solder from them has shorted the terminals. I will clean up, post photos and see where we end up.

As I've said, If you're gonna try this people, deffo beware and think seriously about de soldering the expansion connectors and maybe the usb socket too.

[Call_me_a_Cab]

Photos: Note the IMU must ave moved when I rushed to unwrap the smoking package, and the small 3 pin component that has came off.







Don't think that worked. They're here:

https://www.flickr.com/photos/131115035@N05/

[tobias]

That is kind of a mess. It must have been pretty hot. It might actually still be fixable but it needs a lot of spare parts and soldering skills to fix it...