heat and power

12 Aug 2010

Dear forum,

I have another problem now, my mbed-uC is really easy being heat after 5minutes operating. When I run it longer it always hang and shut down, sometimes after 20minutes operating. Sometimes the LED is still on but the process stopped.

Other thing is when I connect the USB to PC without applying Vin, the mbed is not on. In the first one week, connecting the USB to PC is enough to power it up. This is not because of less power source on my USB port, because other device powering is satisfied by that and I use the same port from the first time using mbed.

Is there anyone has the same problem?



12 Aug 2010

How are you powering your peripherals? Are you using the regulated rails on the mbed? Also, try not to draw too much current from the Digital IO. This could heat up the chip. For me, the chip is usually warm to the touch while it's running.

The USB power problem has been mentioned on the forum before. For me, it happened when I shorted the 5V rail to the 3.3 rail. The device wouldn't power up from the USB for a few hours but eventually it fixed itself somehow.

12 Aug 2010

Raharja, It sounds to me like you have a faulty/broken mbed board... it should never get hot enough to shut itself off or damage itself unless it's broken or you're doing something very wrong!

13 Aug 2010

After I changed the power input from >5battery (:several batt.s) to 5V regulated, shut down caused by overheat no more happen. Thanks, but USB still can not power it up and I already checked no short between 5V-Out to 3.3V-Out.

13 Aug 2010

I am not sure if you read this or not, so have a look.. It might be helpful...