Working temperature of Cerb 40 II

NETMF & Gadgeteer
1

As soon as I power up the Cerb 40 II the surface temperature of the chip immediately goes to around 65⁰ C, which is near the limit of the listed operating range. In comparison the Cerberus board only gets to 24⁰ C when under load.

The Cerb40II will still accept firmware and I can run some code on it but I’m concerned that it’s headed for imminent failure. Does this mean that I’ve toasted the Cerb40II?

2

Is anything else attached? It sounds like you might have a short somewhere.

3

No, nothing else attached. I even took it out of the breadboard and got the same results.

4

You should also pull out a magnifying glass and inspect the board for any stray solder bridges.

5

How are you powering your board? Did you try it with nothing connected but power?

6

Right now I’m just using the USB for power. Same USB cable I use for the other boards so I don’t think it’s the cable.

I was powering it through a breadboard power supply and I suspect that have cause the problem.

I didn’t notice the temperature of the CPU before but now I notice that it’s hot. So the 65⁰ C is out of the ordinary, right?

7

Yes, very out of the ordinary.

8

Thanks, that’s all I needed to confirm. I’ll put this aside and wait for another sale of the ones with the header pins already attached.

9

You may be due an RMA if the board is defective. Has it ever been attached to anything or is it like this from the beginning? You may want to post some high-res photos of the board for GHI to verify the assembly looks correct.

10

If it’s heating up like that it could be there is a pin that is shorted somewhere (i.e. something drawing to much current). Check the voltage across the power. Also, does the chip actually work at those temps?

11

Chip seems to actually works when at the high temp. All I’ve tested was to flash the firmware and made a couple of LEDs blink.

Thanks for all of the responses but I’m guessing that even though it’s working that it won’t work for long. I’d also assume that it was a misstep on my part that was the cause so I won’t be asking for an RMA. I’ll give up on this and use it for solder training.