Hi.
I have a Walkera Mini Lama v4-5 model helicopter, with two brush motors
and two servos controlled by a 4-in-1 radio.
It lost radio control (my fault, switched off the transmitter), broke a
blade and the two rotors got tangled into each other. Engines got
stalled, but were trying to spin at full power. Absorbed too much
current, and something blew inside the 4-in-1; now it responds to servo
movement, but doesn't spin up the motors. A new radio is quite
expensive here, so I'm trying to repair the one I have.
Here are the pictures.

http://img83.imageshack.us/img83/6867/lamacent48lw.jpg
http://img84.imageshack.us/img84/703/lamacent31tv.jpg (the board is
horizontally reversed here)

In a RC forum they suggested I replace the two mosfets you can see in
the first image on the right, by the engine contacts.
Testing them with the diode function of my multimeter gave incoherent
results (extremely brief, high reading, followed by nothing), so I
assumed they were toast as per suggestions. I removed them and soldered
two new mosfets.
Nothing changed. What's more, the new mosfets tested in the exact same
incoherent way. I removed them from the circuit and retested them, and
they are ok. This means the old mosfets were probably ok and the fault
is somewhere else.
Also, with the mosfets disconnected and the circuit off, I measured the
resistance of the two engine contacts. One tests open, the other has a
130ohm resistance (if I'm reading the multimeter right). This seems
weird, as the two connections are supposed to be the same.
Any ideas?
PS Keep in mind that while not absolutely totally
electronic-illiterate, I'm very much new to this stuff. Please be
specific about components and what I should do.
Thanks.