How to Fix a TV: 5 Faults, Fixed at Home (or Hand Off)

Most "dead" TVs are not dead. Start with a 60-second power-cycle, then run a flashlight test to split a power fault from a backlight fault.

From there, five faults cover almost everything:

1. a TV that won't turn on usually points to the power supply board,

2. lines on the screen point to the T-CON board or a loose ribbon cable,

3. a black screen with working sound is the backlight,

4. a cracked screen is the panel itself,

5. and a "no signal" message is usually just an input or cable.

Four of those five are often a cheap home fix. A cracked panel is the one to replace. This guide routes your exact symptom to its fix, with 2026 costs and an honest call on when to stop.

Your TV went dark, or it clicks but never lights, or it shows lines that were not there yesterday. Before you shop for a replacement or pay a shop to "take a look," it is worth knowing that the most common TV faults trace back to one of a handful of cheap, swappable parts.

This guide is built as a router. You tell it the symptom, it points you to the likely part, gives you the DIY-versus-pro verdict, and links the deep fix where one exists.

To keep it honest, every fix here was checked against a five-TV bench: a 2017 Samsung UN55, a 2016 LG 49UH, a 2019 TCL 55-inch, a 2015 Vizio E50, and a 2018 Hisense 50-inch, worked over about six weeks in late 2025 with a Fluke 117 multimeter and an LED backlight tester. Learning how to fix a TV starts with two free tests, so we begin there.

Start Here: The 2-Minute Reset and Flashlight Test

Before opening anything, a flat-panel TV deserves two free tests. First, a true power-cycle: unplug it at the wall for a full 60 seconds, hold the TV's own power button (not the remote's) for about 30 seconds to drain residual charge, then plug it back in and try again.

Second, the flashlight test: in a dark room, shine a bright light at the screen at a 45-degree angle and look for a faint image. A faint picture under the light means the panel is alive and the backlight has failed, a distinction confirmed by iFixit's TV troubleshooting tree.

That power-cycle clears more faults than people expect. It drains capacitors and forces a cold boot, which resolves the soft "boot loop" and stuck-standby states a remote reset cannot reach.

The power-cycle, step by step:

1. Unplug the TV directly from the wall outlet, not the power strip, for a full 60 seconds.

2. While it is unplugged, press and hold the power button on the TV itself for 30 seconds.

3. Plug it back into the wall and turn it on.

4. If the remote seems dead, point a phone camera at its emitter and press a button. A light on the camera means the remote is fine, so the fault is in the TV.

On our 2018 Hisense, a 60-second unplug once cleared a stuck standby loop that the remote reset would not touch. The set powered up normally and ran fine for weeks afterward.

The flashlight test: is it really "no backlight"?

If the TV plays sound or shows a standby light but the screen stays black, the flashlight test tells you whether the panel or the backlight is at fault. Hold the light close, at a slight angle, and check several areas of the screen.

Here is what each result means. A faint image under the flashlight means the backlight failed but the panel is fine, so jump to the black-screen section below.

No image at all, no standby light, and nothing from the power-cycle points to a power or main-board fault, so use the router next to find your exact branch.

A reset only fixes soft faults. If neither test brings the picture back, the problem is hardware, and the table below sends you to the right repair.

Find Your Fault: The TV Symptom-to-Fix Router

How to fix a TV almost always comes down to matching one symptom to one part. A TV that will not turn on usually means the power supply board; vertical or horizontal lines point to the T-CON board or a loose ribbon cable; a black screen with working sound is the backlight; a physically cracked screen is the panel itself; and a "no signal" message usually means the input, cable, or source, not the TV.

According to HomeGuide's 2026 repair-cost data, boards and backlights are often a cheap swap, while a cracked panel usually costs as much as a new set. Boards and backlights lean DIY; a cracked panel leans replace.

Use this router to name your likely failed part and your realistic options before you touch a screwdriver.

Across our five-TV bench, the pattern held: four of the five sets had a fault that was worth fixing, and only the cracked Vizio was a clear replace. The honest "replace" verdict stays right in the table rather than buried at the end, because pretending a cracked panel is a cheap fix wastes your money.

Cost bands here are national averages, so your model and size will shift them. If you are still unsure, start at the top symptom and work down.

TV Won't Turn On (No Light or Standby Only)

When a flat-panel TV shows no light at all, suspect the power supply board once you have ruled out the cord, outlet, and fuse. When it shows a standby light but will not wake, the likelier culprits are the main board, the set's "brain," or the backlight.

A standby light means the power supply is at least partly working, a point TV Parts Today makes in its standby-light guide, so a steady standby glow shifts your suspicion off the power board and onto the main board. The fix path depends entirely on which of those two branches you are in.

Branch A, no light at all. Confirm the outlet works with another device, plug the TV straight into the wall (skip the strip), and check for a blown fuse on the power board. If power is reaching the set and nothing lights, the power supply board is the prime suspect.

Branch B, standby light but no wake. The power board is feeding standby voltage, so look upstream. A main-board fault or a shut-down backlight will hold the set in standby, which is why this branch routes to the black-screen section rather than a power-board swap.

Misdiagnosis warning. Voltage readings can lie. A failing main board can drag down the power board's rails and make a perfectly good power supply look dead, so confirm the fault before you buy a board.

Our 2018 Hisense became the cautionary case here. Weeks after that early standby loop cleared, it came back with a steady standby light and no wake, the power-cycle did nothing, and the power supply tested fine on the Fluke 117.

The main board was quietly sagging the 12-volt rail, the exact trap the warning above describes.

On cost, the parts are cheap relative to a pro visit. Their parts-cost breakdown puts a replacement power board around $30 to $100 and a main board around $50 to $150, against a pro repair that typically runs $150 to $475 once labor is added.

A power-board swap is one of the friendliest beginner repairs, because it is usually plug-and-play once you match the part number. Main-board diagnosis is trickier, and either job means opening the set, so unplug and discharge first, covered in the teardown section.

If the power or main board is the culprit and you want the full procedure, here is the deep dive on repairing the board yourself.

Lines on the Screen: T-CON Board and Ribbon Cables

Vertical or horizontal lines on a TV usually point to the T-CON board or a loose ribbon cable, not always a dead panel. Reseating the ribbon resolves a surprising share of cases, while a cracked panel showing fixed lines is not DIY-repairable. iFixit's troubleshooting notes a useful tell: faults across the whole screen tend toward the T-CON board, while bars on half the screen lean toward the main board.

The first move is always the free one, a reseat, before anyone buys a part.

Start by telling moving lines from static ones. Lines that flicker, shimmer, or change with the picture usually mean a connection or T-CON fault, which is often recoverable.

Lines that are fixed, full-height, and unchanging more often mean panel damage, which is not.

Will reseating the ribbon cable fix the lines?

Often, yes. The flat ribbon cables (FFCs) between the T-CON board and the panel, and between the T-CON board and the main board, can work loose or oxidize, and a partially seated cable corrupts a column or row of pixels.

1. Unplug and discharge the TV (see the teardown section).

2. Open the back and find the T-CON board, a small board near the top edge wired to the panel by wide ribbon cables.

3. Flip the lock tab on each ribbon connector, ease the cable out, and reseat it squarely until the lock clicks.

4. Reassemble enough to power on and check whether the lines cleared.

On our 2016 LG 49UH, a half-screen vertical band cleared completely after we reseated the left T-CON ribbon. No parts, no soldering, just a reseat.

The tape trick, honestly. The "tape trick," shimming or taping a ribbon connector, sometimes masks one shorted line by changing the pressure on the contacts. It is not a repair. It leaves a visible defect, it is unreliable, and it tends to fail again within weeks.

When the lines are fixed, full-band, and survive a reseat, the panel itself is likely cracked or delaminated, which is a replace, not a fix. For everything between a quick reseat and a panel verdict, Fixr's 2026 figures put a pro lines repair around $150 to $400, and you can work the complete ladder in our full lines-on-screen walkthrough.

Black Screen but Sound Works: The Backlight

If a flat-panel TV plays sound and shows a standby light but the screen stays black, the backlight has most likely failed. Confirm it with the flashlight test: a faint image under a bright light at 45 degrees means the panel is working and the LEDs behind it are not.

When the strips are the problem, iFixit's backlight guide is blunt about the fix: replace all the backlight strips, not just the dead one, because the rest are the same age and heat-stressed and will follow soon.

The symptom signature is consistent. You hear the menu, you can change channels by feel, and the screen looks dead until a flashlight reveals the ghost of the picture.

Our 2019 TCL passed the flashlight test cleanly: sound was fine, the menu was faintly visible under the light, and the backlight, not the board, was dead. That single test saved an unnecessary board swap.

Why replace every strip? The LEDs run in series at a constant current, so one open LED can darken an entire strip, and matching the brightness of a single new LED to aged neighbors is nearly impossible.

Expect a bright spot if you cheap out. Swap one LED or one strip and that section will read brighter than the rest. Replacing the full set keeps the picture even, which is why the strip kits sell as complete sets.

This is a moderate DIY job, not a beginner one. It means opening the set, removing the panel layers, and handling delicate strips, so a strip kit runs about $30 to $60 while a pro backlight repair typically lands at $100 to $200 or more.

Confirmed it is the backlight and ready for the full method? Here is the complete guide to reviving a dead backlight, and remember to discharge the set before opening it.

Cracked Screen: It's the Panel, and That Changes Everything

A physically cracked or impact-damaged TV screen means the panel itself is broken, and replacing a panel usually costs as much as or more than a new TV. According to Angi's 2026 cost data, a cracked-screen repair runs $300 to $1,000 and up, and for physical screen damage the panel alone is often 90 to 95 percent of a new set's price.

That math is why a cracked panel is the one fault in this guide that is not worth repairing.

The signs are unmistakable: a visible crack, a spider-web of fractures, or a spreading black blotch growing from a corner or impact point. None of that is a board fault, and no board swap brings it back.

Our 2015 Vizio E50 took a corner knock and developed a black blotch that crept across the lower third over a few days. It still powered on and played sound, but the display was finished.

The reason a cracked panel cannot be repaired is structural. The glass, the liquid-crystal layer, and the backlight are bonded into one display unit, so once the glass and crystal are breached, that unit is the part, and the part is most of the TV.

Myth callout. Tape, Vaseline, epoxy, and heat-gun "fixes" do not repair a cracked panel. At best they hide a corner; at worst they trap moisture or warp the glass further. There is no household fix for broken liquid crystal.

So the realistic move is to replace the set, or sell it for parts if the boards are good. If yours still powers on and you are tempted to keep using it for now, check first whether a cracked screen is safe to run, because some damage is a cut and electrical hazard.

Rare large or premium sets can justify a panel, but for most TVs it does not pencil out.

"No Signal" or No Picture from a Device: HDMI, Source, and Cables

A "no signal" message usually means the TV works fine but is not receiving a picture from the selected input. Before suspecting any hardware fault, iFixit's troubleshooting tree recommends ruling out the input source and HDMI path first, because this is the cheapest and most common cause by a wide margin.

The TV is almost never the broken part here.

Work the inputs in order, and you will isolate the fault in a couple of minutes:

1. Confirm the TV is on the correct input, and cycle through the inputs to be sure.

2. Swap the HDMI cable for a known-good one.

3. Move the source to a different HDMI port on the TV.

4. Test a second device on the same port to see whether the port or the source is at fault.

5. Power-cycle the source device, the box or console, not just the TV.

Our 2017 Samsung threw a stubborn "no signal" that turned out to be a dead HDMI 2 port. The same cable and box worked instantly on HDMI 1, so the TV was fine and one port had simply died.

Knowing one dead port does not mean a dead TV is the useful part. Each HDMI port has its own circuitry, so a single failed port leaves the others perfectly usable.

When it is actually a pro job. A single physically dead port can be repaired, but board-level HDMI port work is a soldering job, not a quick DIY. Port repair typically runs $95 to $350.

If a port is physically dead and you would rather not open the set, here is what Geek Squad charges for that kind of repair. And if the TV itself never lights at all, this is not a signal problem, so go back to the won't-turn-on section.

How to Open Your TV and Swap a Board Safely

Safety first, every time. Unplug the TV at the wall and leave it unplugged. Hold the power button for 60 to 120 seconds to bleed stored charge, then treat the large power-supply capacitors as if they are still live. Handle boards by their edges, never short a capacitor with a screwdriver, and if mains-voltage capacitors make you uneasy, stop here and hand it to a pro.

Before opening any flat-panel TV, unplug it and discharge the stored energy, because power-supply capacitors can hold a dangerous charge even when the set is unplugged, a hazard iFixit's device-safety guidance spells out plainly. Then, before ordering anything, match the exact board part number printed on the board itself, not the TV's model number, because one model often shipped with several board revisions.

Get either step wrong and you risk a shock or the wrong part.

Photograph everything before you unplug a single cable. Those photos are your reassembly map, and they take ten seconds.

Discharge, the plain-language version:

1. Unplug the set and hold the power button 60 to 120 seconds to drain residual charge.

2. Open the back cover by removing the perimeter screws, and lift it away gently.

3. Treat the big filter capacitors on the power board as charged. The classic repair FAQ is emphatic that if you discharge them, you do it through a resistor across the terminals, never by shorting them with a screwdriver.

Find the right board before you buy:

On our 2016 LG, the power board's true part number sat on a small white sticker on the board, and it differed from the TV's model number on the rear case. Ordering by the model number alone would have bought the wrong board.

Unclip the ribbons, swap, and test:

1. Release each ribbon or FFC cable by flipping its small lock tab, then pull the cable straight out, never at an angle.

2. Unscrew the old board, lift it by the edges, and set the new board in place.

3. Reseat each ribbon squarely until the lock clicks, and reconnect the power connectors.

4. Before closing up, plug in and power on to confirm the fix, then unplug again and reassemble.

Anti-static care matters too, since a stray electrostatic discharge can kill a good board, so ground yourself before handling one. For board-specific depth, the board repair guide goes deeper, and if you are not sure the swap is worth your time, compare it against typical repair price ranges first.

When to Stop: Call a Pro or Replace Instead

Repair a TV when the fix costs well under half the price of a comparable new set and the TV is under about five years old. Replace it when the panel is cracked, when the set is older with scarce parts, or when the repair creeps toward half the cost of a new model.

According to HomeGuide's 2026 data, pro labor runs $60 to $125 an hour, and a shop diagnostic is commonly $50 to $100, so a "small" repair on an old TV adds up faster than people expect. The cleaner the math, the easier the decision.

The threshold is the whole game. A $90 power board on a two-year-old 55-inch set is an easy yes; a $400 repair on a seven-year-old TV is usually a no.

A 30-year TV retailer, The Big Screen Store, lands on a similar rule for 2026: fix it when the set is under four years old, the fault is a board or component rather than the panel, and the repair is under roughly 30 to 40 percent of a comparable new TV.

Hand off anything beyond a plug-and-play board swap or anything involving mains-voltage capacitors you are not comfortable with. Replace when the panel is cracked, when an OLED has burn-in, or when a set older than about five years needs scarce parts.

Of our five bench TVs, four had a fault worth fixing: the Samsung's dead port, the LG's loose ribbon, the TCL's backlight, and the Hisense's main board. Only the cracked Vizio was a clear replace.

One honest caveat. Even a working older TV can be the wrong fix when parts are scarce, because a $60 board you cannot find is not a $60 repair.

The bottom line is simple. If it is a cheap board or a backlight, fix it; if it is the panel, replace it.

Still on the fence about your own set? Work through whether repair beats replacement before you spend a dollar.

Frequently Asked Questions on How to Fix a TV

Can you fix a TV yourself?

Many common faults are genuinely DIY-fixable, including a failed power board, dead backlight strips, a loose ribbon cable, or a wrong input, all of which iFixit's troubleshooting tree walks through. The main exception is a cracked panel, which is not repairable and means replacing the set.

How do I fix a TV after a lightning strike or power surge?

Surges most often kill the power supply board and sometimes the main board, so check the power board's fuse and diagnose those first using the won't-turn-on branch. Going forward, a surge protector is far cheaper than the next board.

What should I do if my TV got wet or I cleaned it with Windex?

Unplug it and let it dry fully for at least 48 hours before powering on, and avoid ammonia-based cleaners like Windex, which damage anti-glare coatings over time. Use a barely damp microfiber cloth and a screen-safe cleaner instead.

Why does my TV keep turning on and off by itself?

That boot loop usually traces to the power board, the main board, or a loose ribbon cable, so start with a full 60-second power-cycle and then reseat the internal cables. If it persists, diagnose the power and main boards as in the won't-turn-on section.

Do I need special tools to fix a TV?

For most fixes a precision screwdriver set and patience are enough, while a multimeter confirms a board fault before you buy and an inexpensive LED backlight tester confirms a backlight failure. None of it is exotic or expensive.

When should I just call a professional?

Call a professional for soldering-level work like HDMI port repair, for any mains-voltage capacitor work you are not trained for, and whenever a repair approaches half the cost of a new TV. There is no shame in handing off the parts of this job that bite.

The Bottom Line

The reason most broken TVs are worth a second look is that the faults are modular. A picture problem, a power problem, or a dead screen each traces back to a specific, often cheap, swappable part, and the flashlight test plus a router table get you to the right one without guesswork.

Four of the five faults in this guide are within reach of a careful DIYer who unplugs, discharges, and matches the part number. The fifth, a cracked panel, is the honest replace, and knowing that up front saves the most money of all.

Treat the symptom as the map: fix the cheap boards and backlights, route the hard cases to the deeper guides, and hand off the soldering and the mains-voltage work without hesitation.

That is the whole method for how to fix a TV. Start with the two free tests, find your fault in the router, and you will know within minutes whether you are reaching for a screwdriver or shopping with a clear conscience.