Fluctuating voltages and power being out on one phase are two reasons why wifi isn’t working after a power outage. There may or may not be damage to the modem.
Normally, a power outage by itself won’t damage a modem, instead it is fluctuating voltages as a result of a fault with the electrical network.
These unstable voltages enter the modem and can sometimes fry the electronics inside. When this happens you should call your lines company rather than your electrician for more details on the cause of the fault. Sometimes you can check the power companies website or social media for live updates about the fault.
This post will give you the two most likely reasons why the wifi isn’t working from the perspective of an electrician.
Wifi Fault Finding
The modem for the wifi contains electronics. It might have ethernet cables plugged into it. These are the components most likely to be damaged after a power outage.
Normally, the modem will be plugged into a wall socket. This wall socket operates on a standardized voltage and frequency which differs. For America this is 110 volts 60 Hertz and for other countries like UK/AUS/NZ it is 230 volts 50 Hertz.
A modem is designed to operate at this voltage. When it changes bad things can happen as I will discuss below.
This wall outlet will have a cable leading back to the switchboard where the circuit is protected by circuit breakers.
Unfortunately, these circuit breakers won’t protect your modem from unstable voltages. Instead a surge protector is required which is covered in the section below.
It is with noting that the problems relating to random voltages have nothing to do with anything on your property, the fault could be with a distant transformer or power line.
Wifi Not Working After Power Outage? – Reason #1
High Voltage
Likelihood: High – a common reason why appliances with electronics fail after a power outage.
Fixable? No, the electronics inside the modem are most likely fried.
High voltage, even if momentary, can cause lots of damage to a modem. This is because a modem contains electronics which require a steady input voltage. When the voltage gets too high it can ‘jump’ or arc – often in spectacular fashion.
Components like capacitors, resistors and semiconductors on the electronic board inside the modem will pop or go bang leaving black ashy spots showing where heat was created. Weird smells can also be generated.
Essentially, these components and electronic components are not worth replacing and the modem itself should be replaced to get wifi going again.
If the modem had ethernet cables attached such as a printer then check that as well. Ethernet cables are not designed to handle high voltages and could potentially need replacing too.
Wifi Not Working After Power Outage? – Reason #2
Lost Power Feed
Likelihood: High – but only if your property is on two or three phase power.
Fixable? Yes, wait for the lost power feed to come back online. Contact your local lines company for more information.
If your property is operating on more than one phase (such as two or three phase power) then it is possible that the phase powering the wifi is still offline.
This means that for the wifi to work again you will need to wait for that particular power feed to come back online or plug the modem into a different power outlet in the home. Contact your local lines company for more information.
Get Surge Protection
As mentioned earlier, high voltages will damage anything with electronics, not just your modem. This includes the majority of modern appliances in the home. From the Starlink dish, microwave, fridge, dishwasher and washing machine to name a few.
A surge protector will divert high voltages when they occur away from your appliances protecting them from damage and saving you money.
This is a smart investment also saving hassle and inconvenience when an outage actually occurs.
A surge protector will also protect your appliances if lighting hits your home. A surge protector is typically found in the switchboard but can also be found in specific devices such as multi boards.
Electricians Perspective
Intermittent high voltage above 110 volts (USA) or 230 volts (UK/AUS/NZ) is the most likely reason why the wifi modem isn’t working after an outage. In this case the modem should be replaced as the electronics inside are likely fried.
If the property is on three phase power then you can also consider that a phase is still offline in which waiting for the power to come back online might solve the problem.
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