What is the voltage in and out for power source?

I dont beleive it needs to be on the label for the power brick. What you can check though is the label on the modem. There it might say what power supply is needed to power it. it should be something like XXV XXA (XX is the number V is volts and A is amps) If it doesnt, you can always take a multimeter, set it to dc 20, and then stick one probe in the hole of the powersupply and the other on the metal casing white it is plugged in and that will tell you the voltage. Also, most of these run either off of 9 or 12 volts so thats a good guide on what to base this off of.

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