It's also possible that it's a joint position or range sensor failure. The motor may be getting driven to a particular position, but the sensor or limit switch is not reporting the accurate position of the joint. The result is that the motor controller doesn't know the joint is at its end of range, and continues to drive the motor, causing the gear clutch to slip.

It could be as simple as a loose cable connector to a switch or variable resistor (VR).

You would need to get the case open to check the specifics.

ScottE -- Member (always) & Moderator (when needed)

As was detailed in a recent thread, most of the gear boxes have an integrated gear clutch that is designed to slip before the motor stalls or teeth are damaged. It's likely that the clicking is the internal clutch that is slipping, in an attempt to prevent any permanent damage.

In spite of those clutches, there are some cases of teeth that have broken off of RSV2 gears. Those typically lead to motions that stutter or slip back to the beginning, rather than pushing hard at the far end of the joint range. The hand grasp rack and pinion gear set has been known to shear off teeth.

In this case I think it's more likely that the limit switch or position sensor is tricking the robot into continually driving the joint past the end of its normal range. Powering up the robot causes it to check a few key motors, and place the robot in a known starting position. If the robot cannot accurately tell where the joint is positioned, it cannot accurately put the joint into a known position.

ScottE -- Member (always) & Moderator (when needed)

Turn it off. It's broken until you take it apart and fix it.

If it was new, I'd advise you to return it.
Since you bought it used, there is likely no return policy, nor any warranty, unless you have the original purchase receipt.

Did the previous owner describe any problems prior to your purchase of it one short day ago?

ScottE -- Member (always) & Moderator (when needed)

The fact that it's whirring, without moving or clicking, means the motor is spinning, but it's not moving the gears that power the joint anymore.

The initial clicking was likely the internal gear box fail safe clutch that allows the gear to slip (click) if the joint is stuck. It may be that you didn't heed the warning the clicking was trying to provide, and the clutch broke.

The only way to know for sure is to have a look inside, as described in the posts earlier in this thread.

It's not difficult to open and have a look around for a loose wire on a position sensor. Now that the motor spins, but the gears don't, there's likely more wrong than just a loose wire on a position sensor.

ScottE -- Member (always) & Moderator (when needed)

One other thing to keep an eye out for when poking around inside an RSV2 is the dreaded "insulation rot" problem. There was apparently a bad batch of wire used in building the robot wire harnesses for some portion of the production run.

If your robot is affected, the insulation on the harnesses in the legs and abdomen will have become brittle and be flaking off of the wires. A pile of multi-colored insulation "crumbs" will be all that's left of what is supposed to be covering the bare metal wires.

The symptoms for this problem is usually a rapid discharge of battery power through shorted wires. There may be heating of batteries, and some smoke coming out of the robot.

If you notice any of these multi-colored crumbs inside your RSV2, let us know, and we can steer you towards the various ways that people have dealt with the problem.

ScottE -- Member (always) & Moderator (when needed)

After you find the gear that is broken let me know and I'll make you one since WowWee does not sell them, This would give me a good reason to post a how-to-make a gear article. after that look for the sensor that controls the motor and look for any loose wires and loose plugs. Once you get to the broken gear part I'll start to post the pictures you need to find all of the sensors and connectors if you can not find them.
Good trouble shooting Mr. Scott!
Jax

ps also look at the V2 arm repair thread I posted this will give you a good idea of what the motor should look like even though they are diffrent from the one I showed when you take it apart and view the gallery as well.

GWJax, To Hack and make mods on robots is a life style and comes natural and not by choice. If a robot has a screw to open it then it must be opened!