Like every other electronic item, a TV is a complex device.
The remote, display, user interface, etc., are some of the less complicated aspects of the unit. Dig deeper, and you’d get introduced to the various complexities and how things work behind its screen.
If you’re someone who does their repairs and troubleshooting, you would know more about a TV’s internals than the average user. For instance, you’d be familiar with the TV fuse and its purpose.
The average user, however, won’t be aware. And it’s okay if they don’t want to know better.
But if you like to know the technicalities of things or want to know your TV a bit more from its inside, starting with a component as small yet critical as a fuse is an excellent way to begin the learning journey.
This article will discuss everything the TV fuse does, how and when it could break, what your options are when it breaks, and loads of other information.
So, here you go.
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What is a Fuse?
A fuse is an electric component found in a variety of electronic goods and not just TVs. It protects an electric circuit from overcurrent and other power supply-related abnormalities, such as current overloading, short circuits, mismatched loads, and equipment failure.
If the circuit is not safeguarded from an overcurrent scenario, the terminal device (your TV or any device it’s fitted in) will experience overheating, causing temporary or permanent damage to the device and, at times, fire.
Electric Fuse Physical Makeup
An electric fuse is usually a ceramic or glass tube. Other materials such as fiberglass, plastic, and molded compressed fiber or mica laminates could also be used.
The fuse has metal contact points at both ends, a wire connecting the two terminals, and a pop-up external signal (usually found only on ceramic or non-transparent fuses).
The wire could be made of aluminum, silver, zinc, or copper. And the tube is filled with quartz sand, a non-combustible material.
The cylindrical shape facilitates carrying all the current passing via the protected circuit. But there could be fuses in other forms or shapes too.
Electric Fuse Working Mechanism
The fuse chemically reacts when there’s a current overload, cutting off the supply. Or the heavy current melts the internal wire, breaking the current flow.
The quartz sand absorbs the pressure inside, preventing the fuse from exploding. And the glass or ceramic tube ensures the explosion doesn’t affect the nearby components. The pop-up indicator goes off when the fuse is blown.
The quickness with which the fuse blows varies based on the amount of current flow and the fuse material. Some fuses blow within 0.1 seconds, and others could take a bit more time. It’s usually milliseconds or instant.
An electric fuse can differ in voltage and current ratings, response times, breaking capacity, etc. “Breaking capacity” denotes the maximum current the fuse can safely interrupt. Depending on the fuse’s build, the breaking capacity would vary.
A glass fuse, for instance, provides visibility, which helps during a visual inspection. But its breaking capacity is also the lowest of all fuse materials.
Ceramic fuses have the highest breaking capacity, making them more suitable for higher voltage and current circuits.
Can you fix a wrecked fuse? No. If a fuse blows, it’s gone for good. You cannot repair or fix the melted fuse wire, which is core to the fuse’s functionality.
Difference(s) Between a Fuse Different and a Circuit Breaker
A circuit breaker works similarly to an electric fuse, with a few modifications in the working mechanism.
When there’s an overcurrent, the circuit breaker trips and doesn’t blow off. And because the switching device doesn’t break after a bout of current overload or short circuit, you need not replace it after every instance of tripping.
When the device trips, it doesn’t switch itself off but moves to a dedicated tripping position between the “ON” and “OFF” states.
A circuit breaker can trip multiple times before requiring replacement.
Although a fuse cannot be reused, it’s more affordable, smaller, and more straightforward. Also, circuit breakers require maintenance for their continued and smooth functioning.
Do TVs Have Fuses?
Yes, TVs have fuses, like other electrical devices. The fuse protects the TV from random power surges or excessive current entering its circuit and damaging it.
A TV’s fuse blows when too much power is drawn into the circuit, or it could be due to faulty wiring or a short circuit (due to damaged wires, moisture, etc.),
Where is a TV Fuse Located?
A TV fuse is on the device’s power supply board, invariably close to one of its corners.
If you’ve never seen a circuit board before, the various tiny components could feel intimidating, and finding the fuse may be tricky.
Remember the fuse’s design or how it looks and the fact that it’s a relatively small component in the overall scheme of the board’s design.
Refer to the TV’s user manual if you still have trouble locating the fuse.
What Does a TV Fuse Look Like?
A TV fuse is a small, cylindrical tube with metal caps at both ends and placed in its holders. The fuse size may vary based on the amp rating and other things.
Some fuses could have pigtail leads soldered into place, also called lead fuses. Some television boards may have surface-mount fuses, which look slightly different.
How to Check If a TV Fuse is Blown?
You can ascertain whether your TV fuse is blown through a visual inspection or a multimeter-like tool—for instance, the Fluke 107 AC/DC Handheld Digital Multimeter .
A multimeter helps check and troubleshoot electrical concerns or irregularities with your TV or any other electrical device.
If the fuse is made of glass, it would be dark or cloudy, or a colored stripe could run down its center. A clear glass fuse is a sign the fuse is in working condition.
On the other hand, a blown ceramic fuse may not look dirty or show no external signs since its opaque.
To confirm things, test it with a meter. You may try the fuse while it’s on or off the board. If the fuse is soldered onto the board, you would need desoldering skills and tools to remove the fuse.
The following are the steps to access the TV fuse and carry out the inspection:
Step 1: Unplug your television to remove its circuit board. Lean the TV against a flat, clean surface for easy back panel access.
You might need a small hex tool set (Klein Tools 70550 Hex Key Set ) or a Phillips head screwdriver (Edward Tools Phillips Flat Head Screwdriver Set ) to remove the back plate.
(Note: Touch the board 30 minutes (at least) after unplugging to ensure that it is completely free of any passing current.)
Step 2: Locate the fuse on the board for a visual inspection. If the fuse looks burnt out or the wire connecting the two ends is broken or looks compromised, the fuse is dead.
But test the fuse empirically with a multimeter to confirm things. Also, a ceramic or opaque fuse would be impossible to check visually.
Step 3: Put your multimeter in diode mode. The display should read OL (open loop), which means there’s no electric current path.
Step 4: Grab the multimeter leads (red and black ones) and place them touching the two sides of the fuse. It doesn’t matter which prong goes where. You may switch the lead sides, and the results would be identical.
If the multimeter reads “OL,” the fuse is dead. But if the meter reads zero and there’s also an accompanying beep sound from the meter (not all multimeters beep), the fuse is operational.
The reading for an operational fuse could be between 0 and 5 Ohms. The fuse could be bad or degraded if the reading exceeds 5 Ohms.
Here’s a video showing how to do it:
When should I consider opening the TV and inspecting its fuse and other internals? If the fuse is dead, degraded, or there’s anything wrong with the TV, it would show through its video and audio.
If the fuse has blown or turned bad, your TV will display a black screen with no audio.
How to Replace a TV Fuse?
If you’re sure the TV fuse is blown, remove the component.
To replace the fuse, however, you must take it out. Even if the fuse is soldered, you can desolder the piece and not replace the entire board.
If the fuse was hand-fitted or plugged, you could pull it out. Ensure you touch the fuse only after all power supply to the board is cut off.
If the fuse is soldered to the board, you may need professional help or take the board to a repair shop.
Don’t attempt the desoldering if you have no prior experience using a solder gun, vacuum tools, a solder wick, and other desoldering tools.
Even the tiniest of errors could damage the board, costing you hundreds of dollars in repairs or necessitating a new TV purchase altogether.
Where to Buy the TV Fuse
You can buy a TV fuse online or at a local store. Finding one online should be straightforward if your TV uses a run-off-the-mill fuse. The Bojack F5AL125V 20-Pack 5A 125V Fuses is a solid replacement fuse.
But if your TV requires a particular fuse, your options may be limited as not every store sells specific fuses for different TV models.
How to Buy the Right TV Fuse?
If you’re getting a replacement TV fuse at a local store, the store personnel will help you select the correct fuse for your TV. But if you’re shopping online, you are by yourself.
Note down some of the key specifications of your blown fuse and ensure the new fuse shares those aspects. Here are some information to note down:
- The exact model of your TV and manufacturing year.
- The TV’s power ratings (in watts) and the old fuse’s voltage and amperage ratings (indicated on the fuse or in the TV’s operating manual).
- The fuse’s size and type (fast-blow or slow-blow).
A fast-blow fuse goes off immediately after the current supply meets the fuse’s amperage rating. A slow-blow fuse can handle more startup surges without blowing.
Amperage rating (A) denotes the fuse’s current-carrying capacity. Voltage rating (V) indicates the highest supply voltage the fuse could safely carry.
What happens if you buy the wrong fuse? Using a non-identical or non-compatible fuse may cause electrocution or fire.
The wrong fuse could cause an overload or fault current, causing damage to the board and, subsequently, your TV unit. Another sign of an incompatible fuse is the device blowing even when there is no electrical fault with your TV.
Therefore, check again if your TV can take any standard fuse or requires a specific kind. It need not be an OEM piece. A third-party direct equivalent would work just fine.
Just because a fuse sits nicely on your TV board doesn’t automatically mean a match. The compatibility must be purely at the amp rating level, besides the physical dimensions.
Find Out Why the Fuse Went Bust
Kindly note that replacing the TV fuse is just one-half of the problem solved. If you don’t know what caused the fuse to blow in the first place, it won’t be too long before the new fuse breaks.
It’s, therefore, imperative to learn what caused the blown fuse, mainly if the fuse concerns arise too frequently. Here are some possible cause-factors:
- Bulged capacitors, smoked parts, etc., on the circuit board.
- If the fuse blew off due to a parts failure in its 5VDC power supply, the small IC (integrated circuit) or microchip would have fried.
- The power strip could have issues.
Fuses can degrade over a period without any apparent cause. It’s, therefore, quite possible for a TV to have its fuse blown for no specific reason.
But if the fuse blows off faster than you anticipated, check the unit enlisting help from a trained professional.
Conclusion
To reiterate, a TV fuse is a minor component but critical to the overall functioning of the device. Because it plays a significant, active role and is not a robustly designed component, the likelihood of it going bad is relatively high.
Luckily, a fuse is easy to replace and also a cost-efficient exercise. The real challenge lies in inspecting the fuse, ascertaining the need for its replacement, and replacing it with a new one.
If you’re not handy with electrical devices or disassembling them, you may have to hire help. And that may cost you some money.
But if you’d like to save some cash there and are technologically inclined, the information above will come in extremely handy.
Catherine Tramell has been covering technology as a freelance writer for over a decade. She has been writing for Pointer Clicker for over a year, further expanding her expertise as a tech columnist. Catherine likes spending time with her family and friends and her pastimes are reading books and news articles.