How to check if my power supply is underperforming?

[va88]

Hey guys, I'm having this issue with my external hard drive disconnecting and I'm suspecting my power supply is underperforming.

It's not the official power supply, it's a generic one I found on a store nerby. Except from this suspicion regarding the external HDD, it never showed any sign of problem.

In the Raspberry Pi there's the lightning symbol that shows the undervoltage situation, what about the Rock64? Is there any log or diagnostic tool to track and see if the power supply is underperforming, or if the USB 3 port is not outputing 5V?
Thanks.

[va88]

I checked the GPIO pins with a multimeter while a USB2.0 HDD was connected to the USB3.0 port.
I'm getting sustained 4,4 to 4,6V in the 5V pin.
Should I conclude that the power supply is underperforming?

Can someone recommend a legit power supply from Aliexpress/Gearbest/Banggood (or somewhere that ships to South America at a reasonable price)?

[gigagames]

Hello,

what are you Power Supply says, how mutch Ampere it can deliver?
The official is 5V - 3A

[va88]

Hello,

what are you Power Supply says, how mutch Ampere it can deliver?
The official is 5V - 3A

The power supply says it delivers 5V3A, but it looks like that's not true.
Under very little load it's below 5V.

I ordered a USB Voltage meter to check the amperage anyways.