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NO GREEN LIGHT (16 x 12-bit PWM Servo Shield)
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NO GREEN LIGHT (16 x 12-bit PWM Servo Shield)

by PrestonAltree on Mon Dec 17, 2018 4:44 pm

Hi everybody,

I'm having an issue setting up my PWM board as a servo shield. The red light is illuminated and the reset button is responding, but despite having +5V DC running into the V+ terminal and ground running to the Gnd terminal, no green light. Any suggestions on how to fix?


EDIT: I should note that it's getting power through a 5V 1A voltage step down regulator from a 9V battery.


Thank you for your time,

Preston

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Re: NO GREEN LIGHT (16 x 12-bit PWM Servo Shield)

by adafruit_support_bill on Mon Dec 17, 2018 5:23 pm

Please post some photos showing all your soldering and connections.

EDIT: I should note that it's getting power through a 5V 1A voltage step down regulator from a 9V battery.

What kind of 9v battery? You will never get anything close to 1A from a garden-variety 9v 'transistor' battery.

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Re: NO GREEN LIGHT (16 x 12-bit PWM Servo Shield)

by PrestonAltree on Mon Dec 17, 2018 5:34 pm

It's definitely a garden variety 9V battery. Am I not drawing enough amperage to power the board?


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Re: NO GREEN LIGHT (16 x 12-bit PWM Servo Shield)

by adafruit_support_bill on Mon Dec 17, 2018 6:16 pm

The solder looks OK. A standard 9v battery is not going to power a servo very well - or for very long. But it should have enough power to light the LED.

Double check the polarity. And if you have a multimeter, measure the voltage at the screw-terminals.

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Re: NO GREEN LIGHT (16 x 12-bit PWM Servo Shield)

by PrestonAltree on Mon Dec 17, 2018 7:18 pm

Interesting, it’s reading about 5.8v on the terminals but still no green LED. Polarity is correct, so I’m not sure what my problem is.

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Re: NO GREEN LIGHT (16 x 12-bit PWM Servo Shield)

by adafruit_support_bill on Mon Dec 17, 2018 7:37 pm

There is a circle on the board labeled "C2". What is the voltage between the two pads inside that circle?

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Re: NO GREEN LIGHT (16 x 12-bit PWM Servo Shield)

by PrestonAltree on Thu Dec 20, 2018 1:55 pm

Hey Bill,

According to my voltmeter, the voltage along those capacitor points is the same as the voltage coming into the circuit. I even swapped over to the recommenced 4 AA battery holder and I’m still not getting a green light.

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Re: NO GREEN LIGHT (16 x 12-bit PWM Servo Shield)

by adafruit_support_bill on Thu Dec 20, 2018 2:07 pm

OK. That shows that power is getting through to the power rails, which means that the LED should have power too. That leads me to conclude that your board has a defective LED. It is probably functional otherwise. But if you contact support@adafruit.com with a link to this thread, we can send a replacement shield.

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Re: NO GREEN LIGHT (16 x 12-bit PWM Servo Shield)

by PrestonAltree on Thu Dec 20, 2018 2:13 pm

Awesome! Thank you so much, Bill!

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Please be positive and constructive with your questions and comments.