Sound but no picture, faint lines, a screen that flickers and dies — each fault points to a different part, and only some of them are worth spending on. Here is how a technician reads the symptoms.
An LED television is really four things stacked together: a power board, a main board, a backlight, and the panel itself. Almost every complaint we get traces back to one of those four, and the difference between a repair worth doing and a television worth replacing usually comes down to which one has failed.
Here is how to read the symptoms before anyone opens the back.
The simple checks first
A fair number of "TV not working" calls end without a repair at all. Before assuming a fault, go through these:
- Try a different wall socket, and check the socket itself works with something else.
- Unplug the TV from the mains, wait a couple of minutes, plug it back in. This clears a surprising number of stuck states.
- Change the HDMI input. A blank screen with a working set-top box is very often just the wrong source selected.
- Swap the HDMI cable and try the other port. Cables fail more than people expect, especially where they are bent tight behind a wall mount.
- Check the set-top box or player separately. A dead box looks exactly like a dead TV.
Reading the fault
Sound is there, picture is black
This is the most common serious complaint, and it usually means the backlight has failed. The panel is still producing an image — there is just no light behind it to make it visible.
Test it in a dark room. Shine a torch at an angle onto the screen from close up, with the TV on and playing something. If you can faintly make out the picture under the torch light, the panel and the main board are alive and the backlight strips or their driver circuit have gone. That is a repair, and on most sets a sensible one.
The screen flickers, then goes dark
Similar territory. One failing LED in a backlight strip can pull the whole string down, and the protection circuit shuts the backlight off. Sometimes it comes back when cold and fails again once warm. Backlight strips are replaced as a set, and a job done properly means replacing the whole strip rather than patching one diode.
The TV will not switch on at all
No standby light, no click, nothing. This usually points to the power board — commonly failed capacitors, a blown fuse or a damaged supply section. A power board is repairable on many sets and replaceable on most. This is often one of the more worthwhile repairs, because the panel is untouched.
Standby light glows but the TV never starts
Power is reaching the set but it is not completing its start-up. That is usually the main board, or a power board delivering some voltages but not all of them. Diagnosis here is proper bench work, not guesswork.
Vertical or horizontal lines on the screen
This is where the news is often bad. Thin vertical lines, a band of colour, or half the screen behaving differently from the other half usually mean a fault in the panel's own driver circuitry, which is bonded to the panel itself. Sometimes a loose ribbon connection can be reseated and the lines clear. Often they cannot. A panel fault is effectively a new screen, and a new screen costs so much of what a new television costs that it rarely makes sense.
Patches, blotches or a cloudy area
Dark or cloudy patches that move with pressure, or a spreading blotch, point to physical panel damage — usually from a knock, from being pressed while cleaning, or from the set being carried by the screen. Not repairable.
A cracked screen
There is no repair for a cracked LED panel. A spider crack, a line of impact, or a black spreading area from a knock is the end of that television. Anyone who offers to fix a cracked panel cheaply is proposing to fit a used panel, which brings its own risks and which you should at least be told about honestly.
Monsoon storms, lightning and surges
We see a run of dead televisions every monsoon, and the cause is rarely the rain itself. It is the surge.
A lightning strike on a line anywhere nearby, or the jolt when supply is restored after a cut, sends a spike through the mains. It can also travel in through the cable or dish lead, which people almost never think about. The usual casualties are the power board, the HDMI section of the main board, and the tuner.
The protection is unglamorous and it works. Unplug the television from both the mains and the cable or dish lead during a storm, especially if you are going out. A surge protector helps with the mains side. If your area is prone to long cuts and rough restoration, do not leave the set on standby through a storm — standby is not off.
Before anything is opened: a TV that has been struck should be unplugged from the mains and the cable lead and left alone. Power boards hold charge in large capacitors long after the set is off, and the back of a television is not a place to explore with a screwdriver. Let someone with a discharge tool and a meter open it.
Repair or replace: how to decide
Three questions settle it in most homes. What has failed? How old is the set? And has it been repaired before?
| Fault | Normally worth repairing? |
|---|---|
| Power board failure | Yes — panel is untouched |
| Backlight strips | Usually yes |
| Main board failure | Depends on the age of the set |
| Loose internal connection | Yes, often a small job |
| Panel lines or driver fault | Rarely |
| Cracked or damaged panel | No |
Beyond the table, two rules of thumb hold up. First, if the cost of the repair approaches a meaningful share of what an equivalent new set would cost, the repair is usually the wrong call — and a panel replacement almost always falls there. Second, a television that has already had two boards done is telling you something, particularly if it has lived through several monsoons on rough supply.
There is one more thing worth saying plainly. An older set that works perfectly well and only has a dead backlight is usually worth fixing, even if it is not a smart TV. A cheap streaming stick on an HDMI port does more for an older television than replacing it does.
Getting a straight answer
The honest way to handle a TV fault is to diagnose first and quote after, because the same black screen can be a fuse or a panel. A technician who quotes a figure on the phone without seeing the set is guessing, and the guess tends to be revised once the back is off.
We do LED and smart TV diagnosis, power board and backlight repair, board-level work where it is sensible, wall mounting and installation. Our charges are on the rate list, GST extra, and any part we fit is billed at actual cost after we tell you what it is. If the set is not worth repairing, we will say so rather than sell you a repair that does not last. You get a bill for every job.
Book through contact and we call back within an hour, or ring +91 96315 11974 between 8:00 AM and 6:30 PM on any day of the week.
We handle TV repair in Sasaram, Dehri-on-Sone, Bikramganj, Nokha and Daudnagar among other towns — same day where we can manage it in Rohtas, Kaimur and Aurangabad, and a scheduled visit elsewhere. The full list is on the service areas page.
Frequently asked questions
Usually a failed backlight. The panel is still making the image, but there is no light behind it. Check it in a dark room by shining a torch at an angle onto the screen while the TV is playing — if you can faintly see the picture, the backlight strips or their driver have gone and that is normally a repair worth doing.
No. A cracked or impact-damaged LED panel cannot be repaired, and a spreading black patch behind the crack confirms it. The only option is fitting a replacement panel, which normally costs so much of what a new television costs that it is not sensible. Anyone offering a cheap crack repair is fitting a used panel.
Thin vertical lines, a coloured band or half the screen behaving differently almost always mean a fault in the panel driver circuitry, which is bonded to the panel itself. Occasionally a loose ribbon connection can be reseated and the lines clear. More often it cannot, and that puts the set in the replace category rather than repair.
Unplug it from the mains and from the cable or dish lead during a storm, especially if you are going out. Surges travel in through the signal lead as often as the mains, and standby is not off. A surge protector helps on the mains side, and after a long power cut let the supply settle before switching the set on.
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