Warning: Do not buy a used cable modem.
As someone who has worked inside technical support call centers for internet users, I have personally encountered these problems with our subscribers who bought a used modem online.
There are several reasons why you would not buy a used or refurbished modem online.
But that does not mean in all cases. There are two exceptions where it is OK to buy a used or refurbished modem which we’ll cover below.
Why not to buy a used modem online
A few buying options come to mind in the case of a used modem. You can buy a used modem pretty cheap on eBay or even Amazon. But the risk that comes with the savings is not worth it.
First, let me state that I worked for Comcast Cable Internet for a long time, and this knowledge is from direct experience as a technician and dispatcher for cable internet.
Every single modem has a unique identifier number tied to it. This is called the MAC Address. The MAC Address is on the actual modem, but it must also be added to the account associated with it for the cable internet to be activated.
You can already see where this is going. If you buy a used modem, there is a high chance it is already associated with an account from the previous owner. This happens because it’s not something your average internet subscriber knows.
Without this knowledge, they just turn around and sell the modem. Or even donate it to Goodwill, where the person you buy it from obtains it to sell on Amazon or eBay.
What does this mean for you? When you buy a used modem, the cable company must put the MAC Address of the modem onto your account to activate it.
In the scenario where you bought it used from a random person, there is a very high chance that it will still be on the original account, which is closed or abandoned. This means you are unable to activate your modem.
The customer service rep will not be able to help you or take your word for it that you have the modem. If this were the case, you could easily deactivate someone’s internet, even by mistake.
Sometimes, they will allow you to bring the physical modem to the nearest brick-and-mortar store to verify you have the exact device you say you do. But this is a hassle and a time waste.
The Modem Belongs to The ISP
In many cases, a subscriber will be provided the modem from Xfinity or Cox, and they never turn it back in. In this scenario, the modem is the property of the ISP and can not be resold. Even if you do buy it online, when you call them, they will tell you this device is their missing property because it was never returned from the previous subscriber.
When is it OK to buy a used modem online
As mentioned, it’s not all doom and gloom. You can buy a used modem from Craigslist, a friend, or a Facebook Marketplace.
Why is this OK? You have the ability to talk to the seller, ask them or request that they call their cable company to have the modem removed from their account before you buy it.
If they bought the modem third party(not a rental or provided by the ISP) and the modem is removed from all accounts, then there is no problem with buying a used modem. If it works, it works. Period.
Buying a used modem could save you a few bucks, but the hassle and possible problems may not be worth it.
Can I Buy A Refurbished Modem Online
This is where it gets tricky. I would not buy a “refurbished modem” on Amazon, eBay, or any random website.
The only place you should buy a refurbished modem is direct from the manufacturer.
There are a few reasons. Unfortunately, the first reason is most sellers on these marketplaces will flat-out lie to you. They will say it is refurbished or even new when they truly have no idea at all and can’t even test the equipment.
The actual modem test benches and laboratories required to certify a modem as refurbished are so expensive that only a select few, including the manufacturer, have access to them.
With 3rd party sellers, they generally just buy “return pallets” from major sources of defective returns. They then turn around and sell it 3rd party as new or refurbished. It’s a good gamble for them because oftentimes, the modems will work for a month, 2, 3, or even 6. So they do not have to deal with returns or problems if they occur.
Another possibility is the modem comes with the wrong power cord, which can be a fire hazard or cause damage to the modem itself by slowly overheating for a long period of time which will reduce the lifespan of the modem.
You also forfeit your warranty when buying from unauthorized sellers.
So the bottom line if you have a trusted source and direct contact with the seller so that you may verify the modem is no longer attached to any accounts, you can buy the modem to save a few bucks.
You may buy the modem if you are sure it is an authorized refurbishing facility.
We would just buy new to avoid any problems, and you get the added benefit of securing a manufactures warranty.