Servo Burnout (MicroMaestro 6-Chan USB)

I am having trouble with the 6-Channel Micro Maestro USB servo controller.
I started by connecting a micro servo (rated 4.8-6.0V) to channel 1, as follows: black wire -> GND, red wire -> PWR, white wire -> SIG

I then connected a 4 x AA NiMH battery pack (4.8V) to the “BAT” pins: black wire -> GND, red wire -> PWR.
At this point, the servo started glowing and smoking (I presume it will also have burnt out the motor).
This is all before it’s even been connected to a computer.

Any suggestions on what I might have done wrong, or is it possible that the servo controller was defective in some way?
I can try again later with another servo, but I don’t want to keep destroying them.

Any help is much appreciated.

Hello.

What you describe should not destroy a servo. The “glowing” part is especially impressive; did the servo have a transparent case? What you’re describing could generally happen from reversed polarity, so I would make sure your battery is wired correctly. Otherwise, perhaps you plugged in the servo or battery backwards once?

- Jan

Thanks for the quick reply.

Yes, the servo has a transparent case - now with a small hole melted in the bottom XD
I’ll check that the battery pack is wired properly, but I’ve used it (and the sevo) before in a R/C plane, and it all worked fine then, so it should be ok - Then I’ll try again with a different servo.

If it turns out that the battery pack is wired wrong, is that likely to have damaged the servo controller as well?

No, that shouldn’t damage the micro maestro since the servo power just goes to the servos. (The logic power supply has reverse protection.)

- Jan