Beagle bone restarts when u touch power supply pin near to board

Dear All,
I have a beagle bone black and im using chipsee 7’'LCD cape. The OS reboots as soon as u touch the power supply port near board. What could be the problem. The same problem im facing in another set of board also.

The most likely explanation is a loose connection, check that all the
power supply leads and board interconnections are sound and tight.

Most likely you have the wrong connector on the power supply where the center pin opening is larger than the pin on the power connector.