V2 Microbit won't work using external battery pack

Have a project that uses to small servo motors, one battery pack (3xAA) and a Microbit to control a small robot. The setup works using a v1 Microbit but when I replaced the v2 Microbit (same code) it does nothing. When I remove the battery pack power and connect one servo to the v2 Microbit directly it works.
I tried to upload some images to help with diagnosis.
Code
Control_robot_servo2

Electronic setup

Picture of one servo connected directly to Microbit
IMG_5261

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Hi Kylie,

Thanks for posting! You drawn schematic looks correct, as the GND pin on the connector on the micro:bit connects to the same GND as USB (I’m assuming that’s your other power source)

image

Could you post a higher resolution image of how you’ve got everything hooked up for us to check over?
-James

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Hi Kylie
Not much capacity in 3 AAA. Maybe you are running out of puff.
Cheers Bob

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Here’s the setup. It works perfectly using a v1 Microbit but does nothing when using v2 with same code and setup.

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Hi Kylie,

I can see most of your wiring is correct, though you are using pins 0 and 1 in your code, while the servos are plugged into 0 and 2.

To rule out any stray connections could you connect your alligator clips vertically to the micro:bit like so?

Also, while this is likely obvious, triple-check that your battery holder’s switch is in the ON position.

Do you have access to a multimeter? That’s my go-to when troubleshooting connection problems like these.

Let us know how you go!
-James

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I have checked power from batteries and battery pack and signal for all wires and the pin 2 connection was simply for the photo. Again I need to state that duplicate code with actually the same setup works when using v1 but not v2. My question is why? I don’t have enough v1 Microbits so need to understand what difference there is between v1 and v2?

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Hi Kylie,

I’m quite puzzled why a V2 wouldn’t be able to drive something a V1 could as the V2 has a larger built-in regulator that is able to provide more power to accessories than the precursor could.
This article breaks down the difference in power supply on the board.

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