Here are the traces I have so far. The photos aren't very clear on the right-hand side, so I did some guessing. Also, there are some vias under U1 that probably go to some U1 pins but I can tell yet. When I receive the boards I'll be able to correct it.

Also, the schematic is interpreted from the photos, so I've organized it as it appears in the images. Once I'm *sure* it's correct, I'll reorganize it to make it easier to read.

Thanks to jrgroucho and others on the net for the original photos.

This is being posted to make you think I'm not just sitting on my sas, even though I have.

Michael

Tracing the S107 PCB, I find that there are two pins on the MCU that appear to be configuration pins. The circuitry shows that they are dedicated to reading a "switch" which is flipped by installing or removing R10, R21, R12, and R22.

If my interpretation is correct, there is a "switch" attached to pin 12 of the chip. If R10 is installed and R21 is not, the switch is on (MCU pin is pulled up to positive voltage). If R21 is installed and R10 is not, the switch is off (pulled down to ground). You wouldn't have both R10 and R21 both installed. Same for pin 13 and R12 and R22.

Now, the real question: what do they do? Debugging/testing mode? Perhaps they turn features on and off..? Anybody want to throw the switches and find out for us? I'd do it but I don't actually have one.

If you're inclined to do it, which is ***AT YOUR OWN RISK***, make SURE you switch the thing off and unplug the battery before each stage of soldering. Also, do not charge the battery with the mods in place until we know what they do. If it f's with the battery charger, bad things could happen. See the video.

OK, look at the photo labeled "bottom" in my earlier post to see the resistor names. Take the resistor R10 and move it to the position at R21. That will turn off the "switch" on the chip's pin 12. Test out the heli and see if anything is different. Then move R12 over to R22, which turns off the "switch" on pin 13, and check it out again. Put R21 back to R10, which turns pin 12 on, and test one last time. Lastly, put R22 back on R12 to set it back the way it was.

Whatever these switches do, it apparently is pretty important, and they designed the board so that they can set these switches at the factory. They were deliberately not set at the design phase of the product, and they are not meant to be changed by the end user.

I would wonder whether this same board is used for other helis and these switches tell it which product it's going in, except that the board is very clearly labeled "S107R5". Hmmmm......

... thinking happens ...

I wonder if it is a channel selection switch for the remote control. I heard that the S107 has three channels so you can use up to three heli-controller pairs in the same room without interference (as long as you have ones set to different channels).

Could somebody just have a look at their S107 PCB and tell me how their board was built; whether they have R10 or R21, and R12 or R22? If there's a mix of configurations out there, that probably means the switches set the IR channel.

Michael

Originally Posted by MaladroitFL

Buyer beware of "Xheli Refurbs" - I'm not blaming XH, they probably got returns, checked them out, fixed any broken parts and resold them as used/reburbished at 19 bucks.

I'm blaming myself.
But I am so angry that I wanna punch my S107 in the face.

Tonight it was running erratically, doing nice pirouettes that I didn't put into the stick. It did some leap frogging -- also unauthorized. But mostly it would just cut out and fall from the ceiling area to the floor.
My designated fly room has 12' ceilings and a tiled floor, so it did not exactly land neatly.

First, I unplugged the kids' XBox360. Maybe it was causing interference.
Then I closed the window curtains and pulled the blinds shut on the sliding door.
Still, it acted like a stubborn wild horse.
I killed the lights...
No light... Now I'm basicallty flying the SYMA in the dark, but it kept on cutting out, doing pirouettes and all the while it was mocking me.

I could feel it saying: "Ha ha! You think you can keep running my LiPo down til I can barely get off the floor? Not his time pal!"

Do I change the board?
Kill all electrical power to my house while flying?
Take it outside, set it on fire and send it into the night sky?

Suggestions anyone?
Thankfully, I had 4 fully-charged eFlite batts so I vented my frustrations on my mSR.
I am calmer now, but still need some advice.
Thanks,
Mac

You might try to rule out the problem being with the controller. Can you swap controllers or anything? If that's not it, I wonder if it really is interference. I would suspect that stray IR signals from another device are much more likely than electrmagnetic interference. Take it to another room or the garage or somewhere that has no remote controls and as few live electronics as possible. See if it runs better there.

If the problem really is inside the heli, I wouldn't be surprised if it were getting noise from somewhere. I might finger a bad solder joint, quite possibly at the IR detector or one of the wire leads (motor and such).

If all else fails, ask it whether it wants to donate its body to science and send it to me. I actually might be able to fix it, and/or I might be able to help us all learn something from it.

Best wishes,

Michael

Has my S107 croaked? Fully charged my 107 just now via the USB port on my computer as I usually do and now the battery power seems very low as only the top rotors spin and occassionaly the boottom ones, however the heli has not enough power to lift off more than a couple inches. What could be the problem here??

Karol

Karol, when the bright light to the USB shows...keep it charging for an additional 30 minutes. Try that first. Just because the light on the USB is bright does not mean it has a full charge.

Mike.

Bought two S107 helis for my grandsons a red and a blue both have R5 boards however one seems faster than the other. How is this possible?

Karol

Originally Posted by Chap1012

Karol, when the bright light to the USB shows...keep it charging for an additional 30 minutes. Try that first. Just because the light on the USB is bright does not mean it has a full charge.

Mike.

Will do, but I was of the opinion that once the charge light is on, no charge is going through to the battery. If this is the case I am assuming that the battery can be overcharged.

Karol

@Karol ... first take off the canopy and check that your lipo is not bubbled, then check the wiring going from the bottom motor to the pcb (front motor w/black insulation on top)... if all that checks out its possible that particular motor is going bad though it sounds like a loose wiring connection somewhere

as far as differing speeds on same version units thats a typical manufacturing/assembly variance, mine are like that as well.

Originally Posted by michaelstoops

All,

I'm looking for used S107 parts to do research on. I want to figure out how they work and I'd be happy to share what I find. I've got a mostly-complete trace of the R5 PCB from photos, but I need the real thing to be sure. The photos I have don't show the power connectors very well and I need to remove the chip and other big parts to look for some traces and vias that might be hiding under there. I know there are three vias under the chip but I can't tell where they go.

I'd take wrecked parts but if I can come up with some live ones I'll see if I can figure out what the unlabeled parts are or at least what they do.

If I can get good enough information I'd like to create aftermarket electronics for the S107. Perhaps a replacement PCB with different features. At the very least, I figure I'll put a tiny MSP430F2013 microcontroller onboard in place of the IR remote control receiver. I'd synthesize the IR control signals to take control of the aircraft. It would be fun to put some optical sensors on the S107 and have it do some tricks like seeking an IR beacon. Put the IR beacon on your dog or kids and have it follow them around. Fun!

Anybody have spare or toasted S107 electronics to donate to analysis for the benefit of our collective knowledge? I'd just buy them but my unemployment means a severe lack of $$, although it does mean I have plenty of time for frivolous hobbies. )

Michael

Check your pm's...

Originally Posted by Karolh

Has my S107 croaked? Fully charged my 107 just now via the USB port on my computer as I usually do and now the battery power seems very low as only the top rotors spin and occassionaly the boottom ones, however the heli has not enough power to lift off more than a couple inches. What could be the problem here??

Karol

Sometimes the outside shaft has moved up a couple of millimeters, and it needs to be pushed down to make the gears mesh properly. Worth a try.

Originally Posted by Verewolf

I'd like to cut some time off the 1 hour USB charging.

I did check eBay for a charger.
Any other suggestions on where to get a Syma AC charger?

Here's a link to the amazon sites selling the chargers:
http://www.amazon.com/gp/offer-listi...&condition=new

Hope that works. I believe this charger is the best option - safer then converted none brand plug chargers and faster then the USB charger. A converted charger may damage the heli charge circuits.

Originally Posted by scorp

@Karol ... first take off the canopy and check that your lipo is not bubbled, then check the wiring going from the bottom motor to the pcb (front motor w/black insulation on top)... if all that checks out its possible that particular motor is going bad though it sounds like a loose wiring connection somewhere

as far as differing speeds on same version units thats a typical manufacturing/assembly variance, mine are like that as well.

I have tried all that was suggested and still no joy. Going to swap the battery which looks just a bit puffy for a 200ma one from a Falcon X heli and see if that helps any.

Karol

Originally Posted by HuhWhat

I believe this charger is the best option - safer then converted none brand plug chargers and faster then the USB charger. A converted charger may damage the heli charge circuits.

I use a mains USB charger plug like they sell for iPhones - it charges my S107 in 45 minutes max. They are very cheap on eBay. Just plug the USB charging lead into the plug and the plug into the mains.

Originally Posted by Karolh

Has my S107 croaked? Fully charged my 107 just now via the USB port on my computer as I usually do and now the battery power seems very low as only the top rotors spin and occassionaly the boottom ones, however the heli has not enough power to lift off more than a couple inches. What could be the problem here??

Karol

Mine does the same, I think mine is a bad motor for lower rotor. ordered new motor should be here today and I can verify.

You can use a couple of AA's to test the motors. I've done it. Don't leave it on too long. Gently pinch the shaft. If it spins, the motor is good. Suspect the battery or charger circuit.
Terry