Hi,

Recently, the power of my house was out. After the power was resumed, three of the outlets in my bathrooms were not able to be used. I've measured the voltage between line and neutral with a DMM and received a very low voltage reading of approximately 0.5V. Between GND and line is 120V (as expected). No device was plugged into any of those outlets. I don't know what to do at this point; could anybody please help me to figure out the problem? I really appreciate any help. Thanks.

Bathrooms require GFCI protection. Look at the receptacle, does it have a test or reset button?

If not check the other two receptacles. When you find the correct receptacle, reset it.

The circuit has an open neutral conductor. Each box between the panel and the outlet being affected will need to be check for a loose or broken connection on the white wire.

Thanks all for your helps.
I've figured out the problem. I've found and reset the GFCI in another bathroom downstair and everything is back to normal. I thought that every single bathroom should has its own GFCI? In this case, only one GFCI is used for all three bathrooms in my house; is this normal?

Sure, it is done often, one GFI device can protect as many standard receptacles as necessary, within the amp ratings of the GFI device.

Because of the symptom you reported:

"I've measured the voltage between line and neutral with a DMM and received a very low voltage reading of approximately 0.5V. Between GND and line is 120V "

I suspect there is still an existing wiring problem. You should not have seen any voltage across the line and neutral AND the line and ground, once a GFI has tripped.