Wondering how to tell if TV power supply is bad? Well, stay with us through this guide!
The power supply of a TV consists of the power cable, TV HW components, and a power source.
To know whether the TV’s power supply is bad, we need to inspect if the TV receives power in the first place, and if yes, determine which failed – the mainboard or the power supply.
To tell if a TV power supply is bad, the first step is to inspect the TV’s power input port, the entire power equipment, and of course, the power source.
For further identification, you can test the power cable using a Multimeter to determine whether the cable works!
Top 5 Symptoms of a Bad TV Power Supply!
Here’s how to tell if the power supply is bad of a TV:
- Unresponsive TV (not turning on).
- TV powers off by itself frequently.
- The screen appears dim & dull.
- Weird TV crackling, or noises.
- A smoke odor of melted plastic.
These are the main symptoms of a bad power supply but when your TV is unresponsive, it doesn’t necessarily mean that the power supply is bad.
In some cases, you might be dealing with a faulty motherboard so let’s unwrap this really quickly!
Bad Power Supply Vs. Mainboard Failure?
The most frequently asked question is how to recognize whether the TV’s power supply is bad or the device’s mainboard has failed.
Well, the easiest way to tell is by looking at the backlight and whether it lights up or not when you power on the television.
Put simply, if the screen lights up in black or blue color, and goes off shortly after, you may be facing a mainboard failure.
In contrast, if the screen doesn’t light up an inch, well, it’s more likely that the power supply is bad rather than a hardware failure with the machine.
How to Tell if TV Power Supply is Bad in Easy Steps?
The power supply of your TV is typically attached to the main board and without a technician’s tools it’s very challenging to determine whether it’s working or not.
So, you should check all of the outside power factors, to determine whether it’s an external or internal power supply fault.
1. Inspect the TV’s Power Port
The first and most important step is to check the TV’s power port. This is the slot or input on the TV’s back panel where the power cable plugs in.
You can straightforwardly identify a possible fault with the input port on the TV, which would justify your concerns about the power supply.
- The TV’s power port should be labeled “DC-IN” and located on the back!
Within the port, you will see a singular pin connector or triple connector based on the model of your TV as well as the power equipment.
Any sign of damage on the TV’s power input port is a prime example of a bad power supply for the TV, and in rare cases, the TV won’t work at all…
Tip: The power cable must be plugged in as tightly as possible!
2. Inspect the Power Connectors
Any smart or non-smart TV’s power equipment consists of a power cable with two connectors on both sides.
One side goes into the outlet and the other side of the power cable plugs into the back power port of your TV. So far so good, but have you checked the connector’s condition?
Here are some of the general signs of faulty power connectors:
- Bent metal connectors
- Obstruction on the tips
- Dust and dirt accumulation
- Melted or burnt plastic
Note: In case no visual defects appear, clean both sides of the cable (both connectors).
3. Verify the TV’s Power Source
The power supply of your TV might be inconsistent or entirely insufficient because of a faulty or defective power source.
So in order to continue the power supply inspection of your TV, you need to first verify that the power source is fully functional with consistent and reliable A/C.
- The easiest way to test the TV’s power source consistency is by using a lamp!
The bulb must be wired so you can plug the lamp (directly) into the power source of your TV and check whether the light is flickering or very weak.
This is a prime example of an electrical inconsistency where it’s either a faulty power outlet or the power supply to your home is bad.
Was There a Power Outage?
Another scenario for (temporal) power inconsistency to your TV and other electrical appliances happens right after a power outage.
There is a certain period after the power kicks back in when the power is fluctuating or not supplying constant A/C to your home’s main circuit board.
4. Inspect the TV Cable’s Body
The physical body and length of the cable are, of course, one of the main factors that you need to consider in order to tell whether a power supply is bad or not.
So, the best next step would be to trace the entire length of the cable and verify that there are no defects in the cable’s body.
Any rips, cuts, severe twists, or live wires are an example of a bad TV power cable and power supply!
There is no way to fix a defect in the body of the power TV cable, so the best next step would be a replacement of the entire power equipment.
We strongly suggest not plugging in and using a power cable with visual defects to prevent a short circuit or a power shock.
Warning: The power cable must not be twisted or under pressure!
5. Test the Voltage via Multimeter!
Alert: Follow proper safety precautions when working with electricity!
The next step is to test the voltage from the output of the TV’s power cable to determine if there is continuity or not.
For this purpose, you’ll need a Multimeter so you can do the measuring:
- First, disconnect any strips or plugs from the outlet.
- Unplug the power cable from the TV’s power input.
- Connect the power cable of the TV to the wall outlet.
- Set up your Multimeter by selecting “AC Voltage”.
- The red probe should go into the positive (+).
- The black probe should go into the negative (–).
- Check for labels on the male end of the power cable.
- Touch the tips of the probes to the power cable holes.
- There exposes metal contacts – positive and negative.
The readings on the multimeter should be showing the standard voltage of 120V AC, but in some regions, the standard is 220V.
What matters is whether the multimeter shows zero or infinite reading which is a sign that no electrical current passes through the cable’s output.
Note: The multimeter voltage readings might not always be exactly as expected and minor deflection does not represent a problem.
6. Inspect the TV’s Motherboard
If you’re enthusiastic to disassemble your television and check the mainboard for any faults, we can only guide you through the process.
This is one of the most-effective ways to spot a bad power supply so continue reading to learn exactly what to do in a step-by-step guide.
Note: The steps below show how to tell if plasma TV power supply is bad!
- First, disconnect the television from the wall outlet.
- Tip: Having the user manual will be of great help!
- Lay down the TV screen on a soft surface (leveled).
- Undo all screws on the back of your television.
- Gently lift the back panel to expose the mainboard.
- Inspect for any blown fuses or melted capacitors.
- Verify that there are no black, burn, or melted areas.
- Check for any disconnected or unsoldered wires.
- Clean any dist accumulation to prevent overheating.
- Use a Multimeter to measure the power supply output.
Alert: If you’re inexperienced with measuring electricity, we strongly recommend asking for help!
Your TV Power Supply is Bad?
Well, no worries!
After all, the TV’s power supply is the main operation driver delivering what’s necessary for your TV to work normally.
When the power supply goes faulty, the damage is not irreversible and the TV could be brought for servicing in a qualified store.
Reminder: If your TV power supply is bad, check your warranty!
Now we know how to tell if TV power supply is bad since we’ve learned everything about the TV power equipment. The fundamental pieces to check are the TV power port, power cable, outlet, and mainboard since they are the prime suspects for bad TV power supply.
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Kevin has over five years of experience working in various Tech startups and providing Technical solutions. He has contributed to many Tech publications and websites.