Mega2560 problems :( not happy

Hello peepz,

So I am having troubles with my boards, starting this weekend i seem to have fried my sainsmart2560 mega8u2, my macbook doesn't find him any more, i tried uploading new software to it but since that didn't work right away i found a cheap mega2560(copy) board so i could continue my work....
here also i fried stuff... starting with the ams1117 but i think also the mega16u2 is dead now it became enormous hot and after my macbook also woudn't find it anymore :*(

what i noticed is that when i use external psu and usb at the same time, my macbook shutoff, my megaboard shutoff... so some kinda shortcircuit id gues....

anybody familiar with my problems?????



..seems like you have burnt something..
Id check that external power_source.
is it 7V..12V, positive center, litte or no ripple ?

yup, think i burnt something to....

this is the psu$(KGrHqIOKosFG8kPDcbjBR2tCEReWw~~60_35.JPG

but since that first problem, macbook and board keeps powering off when external source and usb power are applied to the board with each adaptor i have lying around...

i have been having problems with the last couple of Mega2560's that I bought, are you using a ethersheild with them? seems that when i have the ethershield on I can't have a external power supply connected. If I do, and I have any device using 5v the mega overheats and resets after about 2 minutes and then just continually resets. If it's plugged in with a usb cord it works fine.