74HC595 on adafruit motor shield v1 overheating issue

Other Hardware Motors, Mechanics, Power and CNC
1

I bought this motor shield a year ago and used it in my projects twice, both times it was receiving power from a 12volt battery pack and there were no issues whatsoever. But now the chip is overheating while using the Arduino uno as the power supply without load. When I ran a example code from the library the chip started overheating and the motor was not receiving any power. Please share any fixes for this issue.Thanks in advance....

EDITED: Just checked the circuit again without the power jumper and the chip began to heat up???:person_shrugging:

2

Not sure at all how You wired it. A pen and paper wiring would be fine.
As a general rule, never use the controller as a power supply. It's not designed and built for that.

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3

What may have happened is that the board shorted out on the metal USB connector on the UNO and burned out the HC595 IC.

Try replacing the HC595 and place some electrical tape on top of the USB connector

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4

Rule #1. A Power Supply the Arduino is NOT!
Rule #2. Never Connect Anything Inductive to an Arduino!
Violating these rules tends to make crispy critters out of Arduinos.

5

What did you connect to that motor shield. Both v1 and v2 of that shield have a design fault that if you connect a servo to the shield, and power the Uno from the shield (leave the jumper on), it will eventually fry the 5volt regulator of the Uno. That will take down the Uno and/or the 74HC595.
Leo..

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6
  1. the motor shield sits on top of the Arduino
  2. In this case I'm running the motor shield using the Arduino power supply since it overheats faster when using the 12volt external power supply.

Note: i recently soldered on some female pin headers so that I could use the analog and power pins. And I checked the continuity incase for any bridging.

7
  1. I'm not currently using a servo
  2. Can I power the Arduino using the shield if I'm not using a servo?
8

How can I check if my chip is shorted ?

9

The question is if you have used a servo.
Once the regulator is toast, it won't magically heal itself.

Yes, if you don't draw any more than 100mA from the Arduino.
An tiny SG-90 servo peaks at 650mA...
Leo..

10

Did you read this (Post #2)?

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11

The Arduino regulator right? Well I'm using a different board now. The one which I did use a servo on is displaying a avrdude error while uploading, could that be the consequence?

12

Hi,
Can you please post a copy of your circuit, a picture of a hand drawn circuit in jpg, png?
Hand drawn and photographed is perfectly acceptable.
Please include ALL hardware, power supplies, component names and pin labels.

Thanks.. Tom.. :grinning: :+1: :coffee: :australia:

13

@Railroader

1700030614732250921296574504277
17000306147322509212965745042771920×1446 276 KB

There are no other components connected currently,even when the power jumper is removed the chip heats up. This is when I'm powering the Arduino in this config

14

You didn't answer this question.
Your UNO possibly has a USB socket, it is metal.
There is the risk of any shield shorting out on the USB socket case.
image image

The solution is to put some insulating tape on the top of the socket to isolate the problem.

Tom... :grinning: :+1: :coffee: :australia:

16

Tried that already, didn't work. Im still wondering how the chip can heat up when the power jumper the removed and the shield is not getting any power whatsoever.

17

The power for the HC595 comes from the UNO 5V, not from the external power.
If the shield is plugged onto the UNO, then it getting power

18

Do shorted ics usually overheat?

19

Sometimes even explode.

MCC3P
MCC3P639×620 145 KB

20

If you have already shorted the chip, then taping the USB socket will not bring it back.

Your picture shows that the ICs are plugin, I would order some replacement ICs and try again.

Tom... :grinning: :+1: :coffee: :australia:

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21

The 74HC595 is the only chip on that motor shield powered from the 5volt supply of the Uno.
If you replace it, then the shield is likely fine. Take care that the chip orientation stays the same.

I fear for the Uno.
You can test it by connecting a 9volt battery to V-in.
Then measure if there is 5volt on the 5volt pin.
If not (higher or lower), then it's toast.

Don't connect it to a laptop/PC.
A fried Uno with motor shield and 12volt supply can back-feed more than 5volt into the USB socket, possible damaging the laptop as well.
Leo..

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