Help! Hitec 7950TH servo working intermittently!

[lksyotas]

History:
I purchased a "like new" Hitec 7950TH servo here in the classifieds a month ago and installed it into my LCC for my steering servo. I have run the crawler with this servo for aprox. 4 hours total. It has worked flawlessly until this morning. I thought I had a dead lipo cause the steering quit responding so I put a fresh pack in and still nothing.

Truck specs:
Spektrum DX3/ SR3000 combo
3S Lipo
Castle BEC - regulated to 7.4 Volts controlling Rx and Hitec 7950TH
Novak Goat 3S/ 21.5T motor, 17 pinion

So, I took the servo apart and found nothing out of the ordinary. All teeth on the gears are fine and circuit board looks ok by eye. Reassembled everything and verified my controller was set properly. I found that if I put a bit of load on the wheels in either direction the servo works but when it returns to its neutral position it will not cycle in either direction. It only works when there is a bit of "help" getting it to start off. I tried a different Rx and still no change so I'm pretty sure it is servo related.

Anyone have any suggestions for me to try next? I will be calling Hitec Monday to see what they have to say. I'm not sure what kind of warranty I have since I'm not the original owner. Thanks for any advice!

[Pintokiller79]

Try unplugging the bec and run the servo directly from the rx. Just a thought, otherwise i would send it to Hitec. They have a great service department. As long as you have the original purchase receipt, and the servo is less than two years old they will fix it or replace it for free. Here is a repair form to fill out and send with the receipt. I sent in a 7955TG that burned up, and it was back in my hands within 2 weeks, no charge. All I had to pay was to ship it to them.

http://www.hitecrcd.com/pages/support/101

[TEDROCKZ]

7.4 volts on the Spektrum Rx is not a good thing. As posted in other threads you should power the servo directly with the CC BEC and power the RX through the ESCs' bec. The y-harness method is your best route.

[lksyotas]

Originally Posted by Pintokiller79

Try unplugging the bec and run the servo directly from the rx. Just a thought, otherwise i would send it to Hitec. They have a great service department. As long as you have the original purchase receipt, and the servo is less than two years old they will fix it or replace it for free. Here is a repair form to fill out and send with the receipt. I sent in a 7955TG that burned up, and it was back in my hands within 2 weeks, no charge. All I had to pay was to ship it to them.

http://www.hitecrcd.com/pages/support/101

Yeah, I am thinking about sending it in but I don't think it will be covered as I'm not the original owner and I don't have the original receipt for the purchase. Figure'd I would try to see if there was something I could check prior to sending it into them for service.

[lksyotas]

Originally Posted by TEDROCKZ

7.4 volts on the Spektrum Rx is not a good thing. As posted in other threads you should power the servo directly with the CC BEC and power the RX through the ESCs' bec. The y-harness method is your best route.

Hmmm, first time I've read that the Rx doesn't handle 7.4v ok. I read a few posts at different forums besides here saying the Rx's could handle 7.4v ok. Here is one directly from Spektrum's website forum:

"What is the voltage range of the SR3000 receiver and can I use a 2-cell Li-Po pack direct?
The receiver can handle up to 9.6 volts. The real limitations are the servos. Some servos are capable of operating at higher voltages while others are not. Check with the servo manufacturer that you're using for specific details."

I hooked my spare SR3000 to it and changed the Castle BEC to 6.0v to try and trouble shoot but it still acted the same.

Also, could you explain what the y-harness method is? I understand running the Castle BEC direct from batt. to servo and just running the signal wire to the Rx and using the Novak BEC to power the Rx but whats the y-harness? Thanks,