mohop

Hi,

I burned out the mixing board of my AeroHawk and I think I could be able to repair it if someone here in this board knows the circuit board mapping. All components are fine, but what seems to have happened is that somewhere in the board there is a missconexion and I need the mapping to be able to repair it.

Thank you all in advance.

meb48

The first thing to check on your Aerohawk board is the "fuses": trace back from where the leads leave the board for the main & tail motors, and you will see at each point a tiny little cylinder, about 3/32 in dia and 1/4" or so long. This is not a component as such, just a piece of conducting metal lightly tacked to the board. If things get too hot, the solder tack melts and the cylinder falls away, thus serving as a fuse.
If you can't find what I am describing but there's a couple of solder pads that appear to serve no purpose, you've lost the fuses and can just tack across the pads (once you have figured out what overheated your board --- remember, you don't have fuses any more!) But it's unlikely you have lost both; chances are the main is missing, not the tail. If they are OK and you've checked continuity, then it's probably your hexfets. Each motor has one; you can replace them with an IRF 7413 hexfet power mosfet, Digi-key part # IRF7413-ND; they were $1.32 each when I replaced one of mine a couple of months ago. SMT is tricky, but there are actually only 3 separate electrical connects to the board (by this I mean some pins are internally tied in the IC; only 3 pins actually matter, though of course using multiple pins improves current capacity), and heat transfer is actually improved if some of your soldering is a little glommy.
If the board is not initializing (showing a steady red LED after 10 seconds), then check the receiver board for proper function. The main board won't initialize until it sees a steady signal and zero throttle from the receiver.
Other than that, I doubt there's an actual schematic around; you have to just find your way like I did, using your electronics skill and a good magnifying glass!

ChrisP

I think I have a similar problem with my Aerohawk, in that the red light never comes on. Without the light on everything works except the tail motor. (doesn't work when rotating the chopper, or from the transmitter stick)

I know tha both motors are fine because I've tested them, and thanks to the previous post I now know both the fuse devices are fine.

What on earth is a hexfet? And what else can I try?

mohop

the problem started like this
the y went to see a friend of mine that rely knows electronics and has 2 hawk´s he has almost spear for Al the components we change the:
fuses
hexfet power mosfet
the red led
and some oder things

the board some times works and some times docent´t like it had a shortcut and we notes that the circuitries burn a track but is inside in the middle of the tow sides of the board looks like the board has internal circuitry that´s wy y Ned the mapping to do the connexion whit cables all components are fine the board is the problem

the red lite only com´s on wen the board Soho's a self check wen everything is fine it lights up if not you are in trouble




the hexfets era the components beneath the white plastic

mohop

sorry forgot to tanks meb48 we try 2 rx and 2 tx

meb48

A hexfet is basically a transistor switch that can supply large amounts of current. I would suspect your receiver; if you have a friend who knows electronics, check the timing of the pulses coming from the receiver with an oscilloscope. I won't go in depth into servo timing specs here, you can find that info all over the net, but the short version is (if memory serves... again, research a little) you want to see a square wave where the pulses vary between 1 & 2 ms in duration; this is how servos and the ESC know what to do (1.5 ms is servo center or 1/2 throttle). On the other hand, I've seen cases where the board won't initialize properly because the transmitter accidentally had the throttle channel reversed ( I know this from when I modified my transmitter to use with the FMA sim, and forgot to set the transmitter back to proper setting for the heli... dumb dumb dumb). What I'm saying is cast your net wide... the problem is not always what it appears to be.

JohnY2004

Many electronic components burned out/failed on the aerohawk helis are due to poor air circulations inside a canopy causing electronic components with overheating issues. I think the manufacturer knew about it and solved these over heating issues by cutting more windows on the canopies, like the police and military canopies.

UKgroucho

The symptoms that you describe could mean that you have a defective gyro... the little silver 'box' on the front of the board (as the board is fitted to the heli). I saw exactly this issue - red light would only come on occasionally - and after much research concluded a gyro failure was to blame. My board / AeroHawk were new so the board went back to the supplier for repair.

There have been some reports that taking the silver cover of the little gyro box and GENTLY pressing the middle of the gyro in can get things working again - but this does not seem to be reliable. You might try this but finding a replacement board might be a better bet.

MTDV

My Feedback: (58)

I found one of a voltage regulator on my Feda Dragonfly was burned, and all servo was dead except the gyro that control the tail motor. I don't know if Feda board is similar to AeroHawk board, but I just want to throw in for an idea. Hope this helps.

MTDV

wozzie

Hi!

any of you perhaps know if I can use the aerohawk board as a mixer? Im using an pg-03 rate gyro, so I need a mixerboard or a revo-mixing and i would like to use a mixerboard. Is it possible to solder this gyro directly on my on aerohawkboard?
greetings.

zeevro

Turn the gyro pot(marked 204) all the way counter-clockwise(thus minimizing it's affect) and hook your PG-03 between the receiver and the board, all other settings remain the same. The Rudder pot in the Receiver is in the bottom(Ch 4).