I have a Mega that started behaving strangely and causing my computer to crash when plugged in. I had a 7.3 volt power source on VIN and USB attached. I tore the setup down to the bare board and I'm getting 1 ohm of resistance from VIN to 5v. I'm pretty sure the regulator is toast but maybe I'm missing something???
Thanks for any input.
No, you are not missing something, it is toast.
The ATmega2560 is no longer reliable, don't use that board anymore. A ATtiny can sometimes survive 7 or 8V, but the ATmega2560 can not do that.
I hope your computer is not damaged. Some USB ports go directly into the processor.
Yep, don't know if you have any fresh, but unless you remove it, you can not use it like this, and there is no guarantee.
It actually shouldn't be a problem, but i admit i have never done that.
He connected 7.3v to Vin, didn't he ? or was there 7.3v on the actual board ?
As I read it, then it is fried and crunchy in its entirety.
A ATmega can sometimes seem to work, but a pin or a section of the chip can be damaged.
I had 7.3v on the VIN pin, and a USB cable plugged in. After I posted I tested putting 7.3v to VIN from my power source and was reading 7.3 on the 5v as well. Nothing else hooked up.
Almost toasted my PC. It went into the bitlocker screen and I don't know the recovery code. A few reboots got it all cleared up luckily. No more off brand for me.
Does it have a polyfuse ?
The polyfuse triggers at 500mA.
Then it's for the bin.
It was acting like a short so I didn't check the fuse. I've already returned it and got an official board that's working fine.
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