What a lovely truck. But there's a story behind it. And some broken stuff too.
Years pass, I pull the thing out of storage. I spend some time, and I get the battery packs (I have a Micro Rock Crawler too..) fixed, as from sitting one or two cells reversed. And I go to drive my truck. I go from reverse, to forward.. there's a puff, and the smell of escaping electrosity. After that, the truck would only go in reverse. I had blown one of the mosfets.
So, frustrated, I called Horizon Hobby. (Horizon owns Losi now.) After a little begging, they found it in their hearts to replace my ESC, in spite of being so deeply out of warranty. Thanks a lot guys! My truck was running again within a week.
That left me with a "dead" $50 reciever/esc package. $50 is a lot of encouragement to fix something. The usual rule with electronics, is you look for something that looks wrong. The truck was happy to deliver clues.
Here's what a seriously blown mosfet looks like. Yes, that's a hole.
Using the 4205 number I was able to identify on the chip, I tracked down the Datasheets. The datasheets seemed sane, so I ordered a few. Sadly, the only decent source was in china, so a month passes....
Removing a chip like that, is a matter of getting all the pins on one side hot enough to flow.. and lifting it up one side at a time. So I added some solder, and got to work. The "near" side was easy. As it's pins are all normal. The far side was a bit more tricky. It's behind a whole bunch of wires.
Here is the cleaned off pads, ready for the new chip.
Here it is, soldered back into place. And before you ask, yes it works. Both forward, and reverse.
I'm glad it worked. Hopefully this might give you confidence to repair your ESC if you ever smoke an IC.