After weighing 100 SMT inductors the mean weight is .1134 Gram at 100 G’s that would be 11.34 Grams (about .4 Oz) pulling against this part. Negating flexing of the board should that be enough to dislodge the component? Did I calculate this wrong?

Reflow is great, but sometimes it’s hard to find a balance between enough heat to properly fuse the larger components without damage to the smaller components. Not saying you should change your process, hell if you only have these three failures then that is great, but as you suggested about G forces I don’t see the component being heavy enough to break from the board unless the board is flexing or it was a bad solder joint. Even at 1 gram the load would be less than ¼ pound.

Regards

Jeff

For the OP- was the missing component found rattling around inside the esc case, or had it completely vanished? That might shed some light on the failure, but 3 of this nature out of thousands is just too random in my mind to be a sign of bad design or soldering or anything else.

Big jump + heavy landing = broken esc > bit of padding under the esc might work wonders, has for me atleast..

Guys! Have some problems in MMM v3 with same elements. Here in Siberia not good with support and I have to repair it myself
Damages 3 elements on foto and I can't find analogues :neutral:

http://img-fotki.yandex.ru/get/4604/...5cde314_XL.jpg
Original

1. Right red arrow. I think this is the transistor 2SC3906K or 2SC4102.
2. Yellow arrow. I think this is a inductor ~ 68 mkH (maybe LQS33N680G or LQG11A68NJ)
3. That a third element (left red arrow) ?

Help please, I want to repair my MMM very very much!!!:cry:

1. NTA7002N
2. 47uh 1008
3. BAT54HT1

Question is - Did you have to check or was that from memory? :whistle:

Actually, that was from memory -- but I think that's correct. :lol:

Pdelcast, thank you very much for the quick response!