Hi guys,
I have the strangest error. When my arduino Nano is not connected to the power everything's fine. If i measure with a multimeter there's no short. As soon as i plug it in, the 5V and the GND are shorted and the thing starts heating up.
If i measure while the power is on my multimeter starts beeping like crazy, indicating that there's a short. As soon as i take it out of power everythings fine and there's no longer a short according to my multimeter. Are there any known problems with this?
There's an opamp and some eeprom in the circuit could they be the cause somehow?
Thanks
lolbroek:
When my arduino Nano is not connected to the power everything's fine. If i measure with a multimeter there's no short. As soon as i plug it in, the 5V and the GND are shorted and the thing starts heating up.
If i measure while the power is on my multimeter starts beeping like crazy
I do not understand what you are describing
Can you please provide a drawing illustrating what the first paragraph means.
Can you please explain what type of multimeter you are using, how it is connected to your circuit, what you think you are measuring and what range it is set to.
Measuring with a multimeter will not tell you anything. What you describe sounds like you have got the power supply the wrong way round.
I think he has the multimeter set to "continuity". Ours beep on continuity to check cable/connector connections and at NO other time.
Paul
My multimeter has never beeped if it's not in diode-testing mode. When you supply power to your circuit, you can not use diode-testing mode (sounds like your doing that).
Hi guys,
My apollogies for not answering. Apparently i don't get mails anymore when i get a reaction to my question.
@Jackrae: The circuit is a bit complex that's why i didn't post it. With the 'beeping' i mean the noise that a multimeter makes when you put it on short circuit measuring mode.
"Short circuit mode"?? Never heard of it. There is a continuity mode, a diode mode, but no short circuit mode. The first 2 are meant to be on unpowered circuits.
Sorry guys, i'm not that experienced with the professional language 
I guess it's the same as diode mode.
Some more info (i couldn't response before because 'i made to many posts in 5 mins): The pins indicated in the image are the 5V and the 0V pins. When the power is off, the resistance between both is infinite (according to the multimeter) indicating that there's no short circuit. As soon as i turn the power on my multimeter indicates resistance zero, the thing starts heating up and the voltage between the '5V pin' and GND drops to zero. I assume that this voltage drop is caused by internal protections of the arduino against overcurrent.
I guess it's the same as diode mode.
No it would be continuity mode.
When the power is off, the resistance between both is infinite (according to the multimeter) indicating that there's no short circuit
That is a meaningless measurement, it tells you nothing.
As soon as i turn the power on my multimeter indicates resistance zero,
NO! NO! NO!
You can not use a meter measuring continuity with the power on, not only is it meaningless it risks damaging the circuit and the meter.
I assume that this voltage drop is caused by internal protections of the arduino against overcurrent.
NO.
The dropping to zero is caused by taking too much current out of the power supply, maybe even the current limit of your power supply kicking in but nothing to do with the Arduino.
the thing starts heating up and the voltage between the '5V pin' and GND drops to zero
That is the real problem.
It could be caused by the voltage to one or more components being reversed.
Your meter measurements are confusing you, your big problem is that something is taking too much current. Can you be more specific than "the thing" is their on part getting hotter than another. Remove the active components one at a time until you reach a point where it is not drawing too much current.
