Just FRIED...my Mega?! Please help this newB...

I connected a PCB that had a hairline short to the Mega and it seems to have damaged the MCU?! The LED does not come on anymore, although the power led and the RX/TX are working. Any suggestions please? Can I use the communication pins and connect through say RS232 etc., in case I have damaged the USB interface? The tools menu still show the COM 1 & 5 which I use 5.

thanks for your help...

Like I said, you'll see the RX and TX LEDs blink as the sketch is uploaded! Also it shows the message as if the sketch was loaded without any errors. Doesn't this mean that the board is OK?! If so then why isn't the LED blinking? Could this mean that maybe just the pin13 is damaged? What other tests could I run to check the health of the board?


p.s. Gurus, please contribute

How about the somewhat obvious one of connecting a seperate resistor and led to another pin ?

Or using a voltmeter on the existing pin 13 to see if there is a voltage going on and off ?

Or combining the two ?

OK pluggy, now you know why they call us NewBees... ;) Well, actually fortunately only the pins I was using at the time which were mentioned in the relative sketch which are pins, 13,12,11 & 10 are not working and the rest seem to be functioning just fine. The maulfunctioning pins are all showing a 3.4 v reading except 13 which shows 0! Any chance of recuperating these pins? Also, any idea what has actually may have happened to cause this malfunction?

thanks again for your help

p.s. also the onboard LED does not function which I guess since probably related to pin 13 it is expected to not function?

Pity its a Mega, you'd just swap the processor out in a Duemilanove. Is there any difference to the voltage setting the pins to output and holding them high or low ? By default they are set to input and are just floating so the voltage showing on them doesn't mean much.

Difficult to say why its gone like it has, although overloading the pins is a good way of cooking them. Tying them to ground with a lump of wire and then programming them high is a sure way of overloading them.

It depends on what you were doing with those pins. An other good (even better) way of blowing them is to define them as outputs, set them low then connect them up to 5V.

Any chance of recuperating these pins?

Sorry probably not.

Well, thank you gentlemen for the advice. I'll leave those pins alone and be happy I still have the rest... ::)