Problem with motor shield

[Jeffkohl]

No led lit on shield but led on on arduino Parts placement and soldering seem ok
I measure 5 v on 5v pin but almost 5 v on 3 v pin.
No load except shield itself

Any suggestions?

[adafruit_support_bill]

Post some photos of the front & back of the board.

The 3v pin is just a pass-through on the shield. There should be no connections to it. Measure the 3v pin with the shield removed. If it is different, you may have a short on the board.

[Jeffkohl]

there does appear to be a higher voltage for 3v point when measured from the motorshield more like 4.5 volts where in the 3-3.5 range on the arduino without the shield plugged in

[Jeffkohl]

other pictures

motorshield-2.jpg (64.4 KiB) Viewed 1551 times

motorshield-1-1.jpg (71.11 KiB) Viewed 1551 times

[adafruit_support_bill]

there does appear to be a higher voltage for 3v point when measured from the motorshield more like 4.5 volts where in the 3-3.5 range on the arduino without the shield plugged in

That is strange. I don't see any obvious shorts. Can you measure the resistance between the 5v and 3v pins (with the shield unplugged)?

You are also missing the header for the "PWR" jumper. If you want to power motors from the Arduino supply, you will need the jumper installed.

[Jeffkohl]

I could not get a resistance reading between 5 and 3 volt pins
which are the two pins that should be jumpered? Don't remember seeing another part except what looked like an extra ceramic capacitor like c2
my grandson did the wiring and we are working together to troubleshoot
should the LED light up when the shield is connected to arduino?

I have had some trouble getting the sample code to compile so not sure what to test next

[adafruit_support_bill]

Not sure where the extra voltage on that 3v pin would be coming from. I'll take a closer look at one of my boards here to see what it could be.

There are 2 holes near the 5v pin and they are labled PWR. You should have a couple leftover pins from the stips of pin-headers that were in the kit. Solder 2 of them in those holes. There should also be a small rectangular jumper block that will fit on those 2 pins.

Unless you are using external power, you need those pins jumpered for the shield to get power from the Arduino. The led will not light unless the shield is powered.

[adafruit_support_bill]

Looking at the board, there is nothing even close to the 3v pin except the 5v and reset pins. If you can't get a resistance reading between the 3v pin and either of the other two, I'd be suspicious of your meter.

[Jeffkohl]

be suspicious of me. this is a new digital meter and I haven't gotten the hang of auto ranging and setting ranges

[adafruit_support_bill]

When you get the header-pins and jumper installed, try pulgging it back into the Arduino and you should see the LED light up.

[Rocobics]

One thing I noticed was different was that you put the 74HC595N in the 16 pin socket? In the instructions it said to put the L293D's (leftmost and rightmost) in the sockets?

I don't know if that's what's wrong, that's just something different from mine/the instructions.

[adafruit_support_bill]

The sockets were a recent addition to the kit and are intended for the L293Ds, since these are the parts most likely to fail if overloaded. Nevertheless, there is no harm in socketing the 74HC595N and it should be functional as built.