Fluctuating voltages preceding a power outage and a lost incoming electrical feed are two reasons why a TV won’t work after an outage.
Normally a power outage by itself isn’t going to cause the TV problems, instead it is the unstable conditions that occur before the outage such as fluctuating voltages (especially high voltages) that can cause problems for the TV.
Fluctuating voltages are caused by a fault somewhere on the electrical distribution network.
For more information contact the company that manages the local power lines. This post aims to explain why a TV won’t work after a power outage and what you should do about it.
TV Electrical Wiring Basics & Fault Finding
TVs are designed to operate at a steady, standardized voltage found at any wall socket in the home. This could be either 120 volts (USA) or 230 volts (UK/AUS/NZ).
Most of the time the voltage found at any wall socket is within a few percent of these ranges which the TV can handle.
The wall socket powering the TV has a cable going back to the main switchboard. At the switchboard the cable for the wall socket is connected to a fuse or MCB which protects the circuit if the TV was to short circuit or overload for some reason.
The wall socket should be protected by an RCD in case an electric shock from the TV occurs.
In older homes, the wall socket may not be on RCD as these were not required until relatively recently.
The incoming supply into your electrical meter feeding your house is required to be steady and fit within specific parameters such as a specific voltage and frequency. This is the job of the company managing the power lines. Let’s look at what happens when it goes wrong.
TV Not Working After Power Outage? – Reason #1
Fluctuating Voltages
Likelihood: High. The electronics inside TVs are susceptible to damage from fluctuating voltages in our experience.
Fixable? No TV is probably fried. Get a surge protector to protect appliances in the future.
High voltages cause damage to the electronics inside of a TV. Even if the high voltage is momentary it can cause irreparable damage to parts inside the TV including capacitors, resistors, inductors and any semiconductor components.
Capacitors on an electronic circuit board inside the TV are especially at risk. These are designed to operate at a very narrow voltage range.
When this is exceeded they short out causing a crack or bang. This tends to leave a burnt or black spot on the circuit board where it occurred.
Weird metallic smells may also be present. The end result is that the TV doesn’t work. Getting it repaired is most likely uneconomical so replacement is the best option. Installing a surge protector will ensure that it won’t happen again in the future.
TV Not Working After Power Outage? – Reason #2
Electrical Feed Is Offline
Likelihood: High – but only if your property is on three phase power. Not likely if you are on single phase power.
Fixable? Yes, wait for the offline electrical feed to come back online. Contact the company managing the local power lines for more information.
If your property is on three phase power it means that you have three different incoming electrical feeds powering your property. These feeds are split to power different parts of the property.
A fault on the power lines could result in one (of the three) electrical feeds going offline.
The solution is to wait for the power to come back online. You may need to contact the company managing the power lines for approximate times when the power will come back on.
Surge Protector
A surge protector will protect your TV and other appliances from voltage surges. It does this by diverting the harmful voltage away from the appliance and discharging it safely to your earthing system. Most modern appliances have electronics such as the AC, fridge, microwave, garage door, and wifi. As a result, surge protection can help prevent costly replacement of these appliances.
A surge protector is a fuse sized device located in the switchboard. These surge protectors will protect all appliances in your home. Surge protectors can also be found on multi boards but surge protection will only be available for whatever appliance is plugged into it.
Electricians Perspective
Fluctuating voltage is the most likely reason why the TV isn’t working after a power outage in my experience. Fluctuating voltages cause damage to the electronics inside the TV. Replacement is the most likely the best option.
We Fix Faults is an electrician blog dedicated to finding and fixing faults. If you’d like to suggest any topics to cover on the blog send us a message above.