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Topic: Is it normal for the Mega Ground to short with 5v? (Read 740 times) previous topic - next topic

quant

My Mega is shorting 5V with Grounds(it has continuity)! Is this Normal? How can it be fixed?
Please help...

thanks

Grumpy_Mike

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(it has continuity)!

How are you measuring this? If it is with a meter on an unpowered unit then this is not the way to measure it.
Does it short out the power supply or does it power up OK?

quant

Thank you for responding.
I am using the Continuity of an Ohmmeter and testing any 5V against GND it beeps?
Also there is a series of 3 little components just above the 5V silk screen between 3V and Gnd and the lower one just to the left of POWER Silk screen ad the two ends of that little component also has continuity?

thanks again for your help

Grumpy_Mike

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am using the Continuity of an Ohmmeter and testing any 5V against GND it beeps?

Then the measurement is totally meaningless.
A meter on continuity puts a small voltage out and measures the current. An unpowerd chip will look like a short or diode drop to this meter. It also does not do the chip any good to be applying voltages to it in this way. All chips will look the same for this sort of test, working or not.

quant

enclosed a pic of the little component to the left of the word POWER.

quant

Thanks again for your great help.
Then how do I check the Mega 5V to make sure it is working all right? When Mega connected to USB and I measure the Voltage, again connecting the Ohmmeter cables Red to 5V and Black to GND it shows -5V?

quant

I just checked again and it looks OK, please disregard the previous post.
Thank you for your help.

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