I just bought the Pololu.
Put 4 batteries correctly and plugged the LCD correctly. (LEDs are not connected yet)
Turned on the power. Nothing happened. 
Hello.
Pololu is our company name, and we sell many different products. Are you talking about the 3pi robot? If you are using rechargeable batteries, have you charged them? If you are using alkalines, are they new? Do you have a multimeter available you could use to measure the battery voltage (you can probe across VBAT and GND)?
- Ben
Yes 3Pi
I measure 6.14V across the 4 batteries
Is that the VBAT at the middle of the robot? It is not connected to other circuits and could not measure any voltage.
Thereās a pin labeled VBAT near the center of the robot, between the two battery holders, and two VBAT pins near the front of the robot. Can you try probing all three pins? If you donāt see any voltage on these pins, there might be a problem with the connection between the battery holders and the board; can you see if the battery holder solder joints look okay? It might help if you could post a detailed/high-res, in-focus picture of the underside of your 3pi. We test each robot before it ships, but maybe something got knocked loose sometime after that.
- Ben
VBAT shows 0V
i could not see any battery holder solder joint
Can you post a picture of the underside of your board (ideally one that will let me see the various parts and solder joints well enough to tell if thereās a problem with them)? Also, there should be a bar code sticker on the bottom of your 3pi with a number written on it starting with ā0Jā. Can you tell me what that number is?
- Ben
oj11870
I could not attach a file The error message is āThe image file you tried to attach is invalid.ā
The picture is at
docs.google.com/open?id=0B0EP0l ā¦ ElZX005RW8
Thanks for the picture. However, what I need to see is the underside of the PCB so I can evaluate the batter holder solder joints and look for missing parts or damage. If your camera has a macro mode, please use that. Otherwise, please hold the camera far enough back from the board so that it is in focus. Even if the robot doesnāt take up the entire picture, there should be sufficient detail in a high-res picture.
- Ben
docs.google.com/open?id=0B-Hitx ā¦ 2E0RWJTUUk
Here is the picture
Thanks Pololu Team to talk to me live.
I donāt notice anything amiss with the bottom of your board. Can you pull off the LCD and take the same picture of the top of your board?
- Ben
I think you uploaded the wrong picture; thatās just a duplicate of the bottom picture.
- Ben
I appreciate your taking the time to upload these pictures; unfortunately, I donāt see anything that would explain your problems, but you might be able to use your multimeter to try to track down why the battery voltage isnāt making it to the VBAT net on the board. Otherwise, I think the next step would probably be for you to send it back for us to look at. If you email us and mention this thread, we can give you instructions for sending it back. If you purchased the 3pi directly from us, please include any information you can that would let us locate the order, such as sales order number or the name of the person who ordered it. If you got it from one of our distributors, please include where and when you bought it.
- Ben