TV not working? The common faults and what each one usually means

Most TV faults fall into a handful of patterns, and each pattern points at one or two parts inside the set. Knowing which pattern you have tells you whether to try a quick reset, whether it is worth repairing, and what to tell the technician so they arrive with the right board. Here is what we see most often in Nellore homes, LED, LCD and smart TVs alike.

Before any of it: switch the TV off at the socket before touching cables behind it, and never open the back cover. The power supply board holds a charge even when unplugged.

No picture, sound works

The single most common fault on LED TVs more than three or four years old. The screen is black or extremely dim, but you hear the channel and the menu tones.

• Faint image visible with a torch held close to the screen in a dark room: the backlight LED strips or their driver have failed. Repairable — backlight fault is ₹499 on our rate card for diagnosis and labour, plus the strip or driver at MRP.
• No image at all, even with a torch: the T-Con board, the LVDS ribbon cable, or the main board. Diagnosis is ₹350.
• Half the screen dark, the other half fine: usually one group of backlight strips, occasionally the T-Con.

No sound, picture works

Check the easy things first: mute, volume on the set-top box as well as the TV, and whether the audio output in the settings has been switched to "external speaker" or "optical" by accident. A new soundbar or HDMI ARC device often leaves that setting changed.

If the settings are right and there is still nothing, it is the speakers, the audio amplifier IC, or the HDMI board. No-sound diagnosis and labour is ₹350.

Will not turn on at all

No standby light, no click, nothing. Try a different socket and a different cable if yours is detachable. If the board is still dead, it is almost always the power supply board — often a fuse or a few swollen capacitors, which is a routine repair. Power cuts and evening voltage swings in Nellore are hard on this board in particular.

Standby light on or blinking, but no start

The set has power but refuses to boot. A blinking LED is a fault code: the power board, main board or backlight driver is reporting a problem. A steady light with no response to the remote or the side buttons can be a frozen main board — unplug for a few minutes and retry once. If it repeats, it is a board repair.

Lines, bands or a half-coloured screen

What you see	Usual cause	Repairable?
Vertical band of lines, appears after warm-up	T-Con board or loose ribbon cable	Yes
One thin permanent vertical line	Panel driver strip	Usually not economically
Horizontal line or bar, fixed position	Panel	Usually not
Picture doubled, solarised or negative	T-Con board	Yes
Crack, spider-web pattern, black blotch	Physical panel damage	No

The short version: lines that come and go, or change with warm-up, are often a board. Lines that are sharp, fixed and permanent are often the panel, and we have a separate guide on when a panel makes the TV not worth repairing.

Picture too dark, flickers, or shuts off

• Dim picture that gets worse over months: ageing backlight. Turning the brightness up hides it for a while and hastens the end.
• Flicker or brief blackouts: backlight driver, a failing power board, or a loose HDMI or LVDS cable.
• Turns itself off after minutes: check the sleep timer and the eco or motion sensor settings first; if it persists, overheating or the power board. A TV pushed into a tight cabinet in a 40°C Nellore room does this.

Smart features and Wi-Fi

Apps crashing, Wi-Fi dropping, the home screen taking ages to load. Most of this is software — storage full, an update pending, a router issue — and we cover the safe fixes in a separate guide. A genuine hardware fault is the Wi-Fi module or the main board; smart or Wi-Fi issues are ₹350 to diagnose and fix.

Remote not working

Batteries first, then look at the remote's tip through your phone's front camera while pressing a button — a flicker on screen means the remote is sending. If the remote sends but the TV ignores it, the IR sensor or the main board is at fault; that is ₹350. If the remote is dead, a replacement remote is usually cheaper than opening it up.

When to call

Anything that needs the back cover off — power supply, main board, T-Con, backlight — is a technician's job. Book the fault that matches your symptom best, mention the brand, size and rough age, and if you have done the torch test, say so; it saves diagnosis time on the day.