Every now and then, I see a flurry of post about v911 RX that refuses to reconnect or rebind to the transmitter. Often times, this occurs following a crash. The symptom is upon plugging in the battery, the RX LED immediately turns solid without blinking, or sometimes, it does a series of rapid blink and then turns solid much quicker than normal.
A number of us learn that the cylindrical crystal that is responsible for the timing of the circuit has gone bad. Replacing it usually fixes the issue. I’ve had this happen on three RX already, and solding on a new one have fixed the issue all three times. So it’s worth a shot instead of throwing the RX away.
For the repair, you need a working 16mhz crystal. You can purchase some on eBay or DigiKey. Or grab one from a non repairable, broken RX board.
The ones I got from Ebay is actually smaller than the original. Whether it’s more dedicate and prone to getting damage as a result, I can’t say yet. Time will tell.
Here’s the two side by side. The original on the left and the Ebay version on the right.
Comparision of the stock v911 16MHz crystal versus the replacement one.
It was easy for me to solder on the new crystal from EBay. And it works like a charm. Here it is soldered to the same location on the v911 RX. It doesn’t dangle past the RX edge like the original one. Just need to glue it down to secure it in place.
Replacement 16MHz cylindrical crystal soldered in the proper location on the v911 RX.
I purchased 50 of them, so let me know if you need one in a pinch.
Hey, thanks ALOT for you repair guide. I currently have to face the exact same problem with my v911 after crashing into a wall ;(
Would you mind sending me 1 or 2 crystals? I dont know what to do with 50 of them when i’d buy them on ebay ;/
i would like to have crystals too.i have the same problem. red light turns solid after 8 blinks.i never do micro soldering like this but i want to learn!!!!
Just shoot me an email with your address. It’s mods@ domain of site.
I see the lots of 50 on ebay and the must ship from HK. Like my last order took over 1 month, no thanks. Do you know the exact specs so I can get the digikey? Otherwise can you send me 2? How did you glue it down? SuperGlue?
I think everyone who I send Crystal to should report their success publicly here. So far, the feedback has been positive. Glad it helped you guys out. I used silicone or white glue to glue things done. Or some plastic dip. Whatever I have on hand.
Hi, I have another problem with main board. It binds OK, servos react properly, but when starting main rotor the power sanks so low that it restarts immediately. Have you faced with problems like this? Admittedly, the reistance of main motor is quite low, around 2Ohms, so the power shold react somehow, but not up to restart, right?
The only time I’ve seen resetting on the board is due to a faulty tail motor or it’s tail wire fraying and the wires and carbon boom together short the RX board and resets it. I believe a quick, dirty but easy test for this is to throttle up and push rudder to the left. This prevents the tail motor from having to spin. If the main rotor spins, then something with the tail is the culprit.
Otherwise, disconnect each motor and isolate the problem. I am guessing it’s one of the motor. Perhaps even the main. If you can solder these wires, then it will help you track down the source of the problem very quickly.
I remember measuring about 8ohms on my main motor. But don’t hold me to that.
Good luck and let me know how it goes. Thanks.
Hi could you send 1 or 2 crystals my way as well, I sent you an email, but I’m not sure if you got it. I’ll be sure to post whether the crystal fixed my problem here.
I’m sorry Louis, I don’t ship internationally anymore. It was a hassle figuring out postage and how to address the letter the last couple of times. And then deal with lost mailing. :( It’ll probably be more cost effective to order from the eBay seller I linked to in the article. It’s worth the time and effort. The people I’ve shipped to have stated that it fixed their RX.
For those in the US, it’s easy to put a .65 cent stamp with a little bubble wrap and anti static bag, and ship it off in my mailbox. Forgive the disappointment Louis.
Hello .
This is anwsome .
Can you send me one crystal?
i will send you a payment before
I didn’t get your email address. Send an email to mods@ this domain and I’ll see what I can do.
Great writeup,this is exactly what I’ve been experiencing. However, I must have a different version heli because there’s a small shiny box on mine where your crystal solders to the board. Can I unsolder this and replace it with a cylindrical one?
I remember reading on the v911 thread that someone did just that Nd it worked just fine for them.
The crystal on the latest board is the small square box top left of the Gyro.
There should be marking related to 16mHz, the frequency of the crystal.
Hopefully someone chimes in and answer your question on the RCG thread with the exact solder joints to bridge.
Hi there, how to search to ebay? do you still got this.
Thanks
I have the 16-mhz
but I can see in the board that it comes with 4 legs..
The newer boards uses a flat crystal that is more resilient against crash damage. And it uses four legs.
I have seen someone commented on installing a regular, two leg crystal. Which two points? I haven’t looked into it yet. Sorry. Perhaps you can find it in a search.