low resistance between gnd and vcc

[santoshkskkr]

I had a card in which while doing some soldering work for mounting component, the resistance between 3.3V and ground came down from 460ohm to 3.6 ohm. I tried to debug it. I found for solder ball which i removed but of no use .I also removed all the capacitors connected to 3.3V and Ground but the resistance is same. What could be the problem and how can i solve it.

 

[KlausST]

Hi,

At 3.3V and 3.6Ohms there is a current of about 0.9A, giving a power of about 3W. That is much heat that you can feel with your fingers. Be carefull.

If you don't want to test with 0.9A, then you may use a current limiting resistor. Maybe 100 ohms to limit to 33mA.
Use a mV meter, connect Gnd to Gnd. With the other wire test several points (starting near your power supply) in your 3.3V line. The lower the voltage, the nearer is the bad connection.

Hope this helps
Klaus