Servo spasms
 

What causes servos to spasm? I have a receiver that causes my servos to spasm. I am using new batteries, 3 different servos, 2 different radios, different channels tried with the different radios, and 2 different trucks. The receiver is a futaba rp123f 75 mhz fm. I am using a 3pk and a associated XP3D with a futaba 75mhz module in it and it doesn't matter which radio I use the throttle spasm out so bad that I can't even run a truck.

Anything I can do about this receiver other than not use it?

Thanks, Uhgg

Are you sure you have your 3PK set to PPM mode for that rx??

If so, have you tried diff set of crystals, didn't see that mentioned in what you've tried.

Yes, 3pk was set to ppm and tried multiple sets of crystals. I have also tried this with different battery packs and a spare servo that I have that isn't in a truck and even that one has spazzes.

Loose solder joint on the circut board in reciever, check around the crystal block. The other culprit could be dirt inside the reciever case that is iron rich that could cause a variety of "glitch" issues. Clean the dirt out as it could be shorting out circuts that aren't suppossed to be touching. I've had BOTH happen to me before. Good luck!

^^^ If you expose the rx to a lot of dirt, dirt can find its way under the pcb in the base of the rx and cause all sorts of probs. Worth taking apart to see.

One of the guys here that seems to work with Futaba mentioned that rxs do go bad due to vibrations and shock from hard landings and etc. Maybe its just gone bad.

Futaba used to repar rx for a very reasonable flat fee. It took a while being the downside. I used to buy used 113ips and got a few bad ones and just send them in for repair. I don't know if they still do this and if so how much, but you could check and see if its an option top consider. Prob just emailing them.

Thanks for the feedback, I am going to try taking it apart and see what I can see.

Try someone else's receiver and see if it still does it. Mine did that and I found out that the antenna was frayed inside the casing. You might want to check the antenna too. It might need replacement, like mine did.