Overheat in the servo pins (Motor Shield v1.1)

by M1ke_89 on Sat Nov 17, 2012 1:05 pm

Hi everyone!

I recently bought a Motor Shield v1.1 and after soldering all the components, put on the motor shield on the arduino (R3), and note that the pins of the servos are heating up. The temperature is not one that can burn the hand, but i don't think that this is a normal considering that i don't have any motor connected.

After this, i had revise some tutorials and images from the motor shield v1.1 and everthing compomponent is correct. Therefore ¿this is normal or not?

Thanks.
M1ke_89
 
Posts: 7
Joined: Sat Nov 17, 2012 11:54 am

Re: Overheat in the servo pins (Motor Shield v1.1)

by adafruit on Sat Nov 17, 2012 1:37 pm

Can you post up a clear photo - both sides? we'll see if anything looks wrong.
User avatar
adafruit
 
Posts: 11642
Joined: Thu Apr 06, 2006 3:21 pm
Location: nyc

Re: Overheat in the servo pins (Motor Shield v1.1)

by M1ke_89 on Sat Nov 17, 2012 4:03 pm

adafruit wrote:Can you post up a clear photo - both sides? we'll see if anything looks wrong.


Here are 2 images. The quality is not very good.

Code: Select all | TOGGLE FULL SIZE
http://s3.subirimagenes.com:81/fotos/8129199foto0036.jpg
http://s2.subirimagenes.com/fotos/8129151foto0041.jpg



(Sorry for the remains of solder paste)

Sure to mention that with a multimeter probe close connections to make sure there is no contact.
M1ke_89
 
Posts: 7
Joined: Sat Nov 17, 2012 11:54 am

Re: Overheat in the servo pins (Motor Shield v1.1)

by adafruit on Sat Nov 17, 2012 6:57 pm

are you sure the pins themselves are hot? not a chip?
User avatar
adafruit
 
Posts: 11642
Joined: Thu Apr 06, 2006 3:21 pm
Location: nyc

Re: Overheat in the servo pins (Motor Shield v1.1)

by M1ke_89 on Sat Nov 17, 2012 7:25 pm

adafruit wrote:are you sure the pins themselves are hot? not a chip?


Completely. The remains of solder paste in the pins begins to melt when connect the arduino to usb. Ah, i forgot to mention that this happens even if retirement the jumper power.
M1ke_89
 
Posts: 7
Joined: Sat Nov 17, 2012 11:54 am

Re: Overheat in the servo pins (Motor Shield v1.1)

by adafruit_support_bill on Sun Nov 18, 2012 9:23 am

The photos are not so clear, but I don't see any obvious shorts. What is the blue wire near the power header in the solder-side photo?
User avatar
adafruit_support_bill
 
Posts: 28118
Joined: Sat Feb 07, 2009 9:11 am

Re: Overheat in the servo pins (Motor Shield v1.1)

by M1ke_89 on Sun Nov 18, 2012 11:01 am

adafruit_support wrote:The photos are not so clear, but I don't see any obvious shorts. What is the blue wire near the power header in the solder-side photo?


If you refere to this part in the picture, that is the recipent of trash from my room. Is only the effect, i don't have any wire.
Code: Select all | TOGGLE FULL SIZE
http://img22.imageshack.us/img22/9950/shieldz.jpg


This situation can be a failure of one of the circuits, especifical the 74595 considering that is CMOS?
M1ke_89
 
Posts: 7
Joined: Sat Nov 17, 2012 11:54 am

Re: Overheat in the servo pins (Motor Shield v1.1)

by adafruit_support_bill on Sun Nov 18, 2012 11:43 am

This situation can be a failure of one of the circuits, especifical the 74595 considering that is CMOS?

Not as you describe the problem. The servo pins are not connected to either the 74595 or the L293D chips. Can you indicate precisely which pins are getting hot?
User avatar
adafruit_support_bill
 
Posts: 28118
Joined: Sat Feb 07, 2009 9:11 am

Re: Overheat in the servo pins (Motor Shield v1.1)

by M1ke_89 on Sun Nov 18, 2012 12:01 pm

adafruit_support wrote:
This situation can be a failure of one of the circuits, especifical the 74595 considering that is CMOS?

Not as you describe the problem. The servo pins are not connected to either the 74595 or the L293D chips. Can you indicate precisely which pins are getting hot?


Considering the way that the remains of solder paste is melt, i say that begining with the central pins(+). Othe thing i just noticed, is that when connecting the shield, the LED in the arduino and the led on the Shield start to blink and exist attenuations like a voltage drop.
M1ke_89
 
Posts: 7
Joined: Sat Nov 17, 2012 11:54 am

Re: Overheat in the servo pins (Motor Shield v1.1)

by adafruit_support_bill on Sun Nov 18, 2012 1:16 pm

It sounds like you have a short between the power(+) and ground pins. Using your multimeter, measure the resistance between the + pin and the ground pin.
Can you get a clearer photo of that corner of the board too?
User avatar
adafruit_support_bill
 
Posts: 28118
Joined: Sat Feb 07, 2009 9:11 am

Re: Overheat in the servo pins (Motor Shield v1.1)

by M1ke_89 on Sun Nov 18, 2012 1:32 pm

adafruit_support wrote:It sounds like you have a short between the power(+) and ground pins. Using your multimeter, measure the resistance between the + pin and the ground pin.
Can you get a clearer photo of that corner of the board too?


The resistence between the (+) and (-) in the servo pins is 1.5k, and in the 5v and ground of the shield is 9.5k initially and begins to increase.
M1ke_89
 
Posts: 7
Joined: Sat Nov 17, 2012 11:54 am

Re: Overheat in the servo pins (Motor Shield v1.1)

by adafruit_support_bill on Sun Nov 18, 2012 1:47 pm

The resistence between the (+) and (-) in the servo pins is 1.5k, and in the 5v and ground of the shield is 9.5k initially and begins to increase.

That sounds about right. It starts out low and increases as the capacitors charge up. If it were a short on the board, it would stay low.

Make sure that the bottom of the board is not contacting the metal housing of the USB connector on the Arduino. Use some tape if necessary to insulate it.
User avatar
adafruit_support_bill
 
Posts: 28118
Joined: Sat Feb 07, 2009 9:11 am

Re: Overheat in the servo pins (Motor Shield v1.1)

by M1ke_89 on Sun Nov 18, 2012 2:00 pm

adafruit_support wrote:
The resistence between the (+) and (-) in the servo pins is 1.5k, and in the 5v and ground of the shield is 9.5k initially and begins to increase.

That sounds about right. It starts out low and increases as the capacitors charge up. If it were a short on the board, it would stay low.

Make sure that the bottom of the board is not contacting the metal housing of the USB connector on the Arduino. Use some tape if necessary to insulate it.


I put the tape on the usb and don't work.

UPDATE:

I retire the servo pins and now the blink of the led is gone.

Thanks for the support and time.
M1ke_89
 
Posts: 7
Joined: Sat Nov 17, 2012 11:54 am