Asked — Edited

Defective Servo Out Of The Box -- Discussion Forum Post Request By Warranty Form

Hi everyone,

I have a new JD Robot!

I'll tread lightly here because I'm in the same sort of chicken and egg situation as in this thread:

I went to the warranty support form that requests that I provide a URL from the discussion form in order to get warranty support. When I try to submit the form, it says, " Warning: Provide the URL to the forum discussion that has helped you identify a defective part. Our customer support person is not able to assist in technical diagnostics. Once you have obtained assistance from our forum, you may provide the URL to the discussion in the above field so we may review the diagnosis to assist you effectively." Ok. So I'm posting this new discussion as requested. :)

I see here in the discussion forum (just above where I am typing), it says, "Note: Technical EZ-Robot questions only! If you have warranty concerns, we ask you contact EZ-Robot directly." This seems to contradict the URL requirement...but I can't submit unless I post here, so here goes:

Out of the box, one of our servos is not working properly. I have self-diagnosed the problem as an electrical engineer with a vast amount of experience with hobby servos. I build other robots and other things with servos (RC planes, etc.). One of the servos out of the box only responds at certain angular positions. For example, with no connection, if the servo is carefully/physically moved to +30-deg off of the 90-degree (zeroed) position, applying power with the controller set to all servos at 90-degrees does indeed move the servo to the 90-degree position. Removing the power and carefully/physically moving the servo to -30-degrees off center (the other direction), then again applying power to the servo with the controller at all servos 90, the servo does not move at all -- no buzzing, chatter, heat -- no nothing. This was discovered when checking the calibration of the servos. All other servos work perfectly using the same controller channel.

I've seen this behavior in servos before that have defective electronics or feedback pot. The gears seem to be fine and the motor works, uh, in one direction...

Does anyone have anything to suggest or add? I'm convinced at this point that it is a defective servo. The behavior is repeatable.

Thanks all!


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You did the right thing - no need to flag as "requiring assistance", as you have seen it's for people requiring assistance. What you can do now is paste this link into the Contact Us warranty section and someone will be in contact with you:)

Enjoy the JD!


Hi DJ:

THANKS! Yes, JD is so awesome! We (my son and I) are so excited to get started with this platform. The best purchase of 2015! We will indeed enjoy JD!

Happy New Year everyone!



@sivads EZ Robot is great at warranty things... However, It is hard for them to give long warranties on stuff like servos as there are so many variables involved. Kind of like warrantying a clutch in a car... If it's dead out of the box then that is another thing and yes they should be replaced under warranty... Anyway, my advice is to buy a few backup servos just in case... If you ever order anything else from ez robot down the road just add a couple of extra servos to your order they are pretty cheap...

You and your son enjoy and have fun...



I bought a JD as a Christmas gift for a 12 year old boy who was very excited about robotics. After opening the box and going through the instructions for assembly it became quite clear that one of the servos was jammed.

The defective servo, on the left ankle of JD, only could be swept in one direction. Unlike the other servos which could move, unpowered, in either direction this one was stuck and didn't move at all. When powered up for the first time all the servos moved both directions but not this one. I have now removed it from the JD and I am requesting that it be replaced so that we can have fun with JD.

Thanks Scott