@Richard R, was that an EZ-B Servo? I was pretty sure that sime if the smoked servos people have had were from reverse polarity and not just from over-stress. Maybe the one you were using has a protection diode? Or maybe I am just thinking about reverse wired H-bridges....

Alan

this is al melted?

@Alan, I have done this with Hitecs, MG996 and an MG946.... These are the servos I use most often... If you plug in a servo backwards you are effectively reversing ground and signal.... not really reversing polarity in the true sense of the word (meaning + and - )..... I have many ez robot servos maybe I should throw one in backwards and see what happens.... You have to consider that if the ez robot servos were to indeed smoke and quit if you plugged them in backwards, wouldn't we have a crap load of posts from people that accidently plugged servos in backwards and smoked their servos?

@Lind 12950

If there are no definite shorts seen, wiring is correct, the fuse is good and the switch is good it may be a bad H Bridge. let us know how you make out. You should then Contact EZ Robot and refer to this thread.

Regards, Ron R

We will continue to monitor your threads.

Since you seem to know your way around a VOM, you could do a test that would check the entire wiring harness at once for shorts.

To do this, however, you would have to disconnect the wires going to the HBridge and EZB4. Perhaps some others as well. I can't say for sure since I don't have a Roli to check with. In any event, once done you could check out the wiring harness for a short using the wires on the switch. Be sure the switch is set to OFF. Yes, I know it's open anyway, but just to be sure. One wire from the switch should go to the battery and the other to the circuitry. What you want to measure across is the switch wire NOT going to the battery and the OTHER end of the battery. Be sure to measure those points with the Volt-Meter first to be certain there is no voltage between the two points. If there is, that alone could indicate a short. and you would not do any ohm-meter test of course. If there is zero volts, then use a low ohm-meter scale, measuring across the same points. That should at least tell you if there is a short.

I have hotwired the faulty power switch and the robot is now working, seems the backward servo was the problem, fuse no longer blowing, but I still need to get a replacement switch for the bad switch. Is this something ez-robot handles under warranty?

Did you send a request through the Contact Us page? When your there make sure you click on the Product Warranty box at the top. It will give you a form to fill out and send in to EZ Robot. Good luck and I'm glad your bot is now working with only a bad switch to replace. Contact Us linky

The fuse is an auto store or maybe even a Walmart part. Installing a fuse of a close value can help prevent a future problem. Use the Contact Us page to make a Warranty claim.

Ron R