Problems with Zumo board v1.2

I recently bought a Zumo kit v1.2 and assembled it with my son. After installing the batteries and turning the power switch on/off nothing happened. Using a multimeter, I verified charge was coming into the board. I also carefully inspected the board and didn’t see any issues with the soldering points. We connected our Arduino uno shield and powered it up using a USB connector and noticed the yellow LED 13 light would come on but not the blue/red power LEDS in the corner of the board. I verified with the multimeter that we were getting power at the ground and 5V input pin although strangely switching the on/off switch didn’t change bring the voltage back down to 0. Any other things I should try? If so, can you please carefully explain what to inspect since I am not very knowledgeable about debugging electronics. Thanks!


Just to be sure, can you check that your batteries are fully-charged or fresh? Can you post pictures that show all the soldering joints on your Zumo shield and post a picture of your Arduino Uno connected to the shield? Also, which pins did you use to measure the voltage when the Uno was not connected to the shield and when it was connected to the shield? What were the voltage readings for each case?

The power switch on the Zumo shield only controls the battery power; it does not control (or disconnects) the Arduino’s 5V output pin. When switching off the power to the Zumo shield, the Arduino Uno board was still being powered via USB, which explains why you saw no effect to the voltage outputted on its 5V pin. You can look at the “Zumo Shield for Arduino, v1.2 schematic diagram” under the “Resources” tab of the Zumo Robot for Arduino’s product page to see which pins are powered by the battery (VBAT).

- Amanda

Sorry for the delay. We disassembled the Zumo and tested the batteries were fully charged. Then we connected wires to the board, turned the switch to on, and verified that the lights still do not come on. Attached photos which show the batteries connected to the board and volt meter showing 6V as well as soldering points. Please let me know if you have any other suggestions or things to try.

It is difficult to see the voltage you are measuring, but it looks like your battery is outputting a little less than 6V. Can you measure the voltage from the charging port on your Zumo Robot and let us know what the voltage reading is? By measuring the charging port, we can verify that the voltage is actually getting to the shield board.

By the way, I noticed some of your pins are not making a good solder connections with the shield. Can you try re-soldering some of the header pins? The solder should look volcano-shaped, forming a smooth slope between the header pin and the pad of the board. You might find this soldering tutorial helpful to you.

- Amanda

As the attached image shows, I followed your advice and measured the voltage from the charging port on my Zumo Robot and it read 6 volts. I can try improving the soldering for the header pins that shouldn’t affect the led lights coming on, correct? Anything further I should check?

You are correct. The soldering state of the Arduino header pins to the board does not affect the power LEDs on the Zumo shield, but you probably will need to re-solder them so that the Arduino can communicate with the Zumo. However, in your pictures, the GND pin of the power switch on the Zumo board is not making a good connection with the pad, which could affect the power getting to the red and blue LEDs. If the power switch is not connected to the board properly, the board cannot be turned on. Can you try re-soldering those three pins, especially the GND pin, and see if that fixes the issue? If not, can you let us know what the voltage reading is when you try measuring VIN (on the front expansion area) and post a close-up picture showing the components in the bottom-left corner of the board near the Pololu logo?

- Amanda