How do I tell if the problem is the backlight?

Turn the TV on in a dark room and shine a torch straight at the screen. If you can faintly make out the menu or channel number, the panel and mainboard are working but the LED backlight is not. If there is neither picture nor sound, the fault may lie elsewhere.

How much does an LED strip replacement cost?

We only quote a firm price after on-site diagnostics — it depends on the screen size, number of strips and parts availability. We agree the estimate before any work begins, and if you decide not to proceed the TV goes back with no obligation.

Can you replace a single LED instead of the whole strip?

Technically yes, but in practice it rarely lasts — the replacement LED may differ in brightness and colour temperature. We usually recommend replacing the full strip to ensure uniform backlighting.

Why does my TV turn on and immediately switch off?

That is a classic LED driver protection symptom — the driver detects a short or excessive current through the burned-out LED and cuts the power. Service diagnostics will pinpoint the faulty component.

What warranty do you give on backlight repairs?

All backlight repairs come with a 3-month warranty on labour and parts. If the same fault recurs within the warranty period we redo the work at no charge.

TV backlight failure — repair in Riga

If your TV screen has gone completely dark but sound and the remote control still work, the problem almost certainly sits in the LED backlight assembly. At the SATER service centre on Silmaču iela 6 we have been diagnosing and repairing TV backlight faults across all brands since 1993.

3-month warranty

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In modern LCD/LED televisions the picture is visible thanks to a backlight layer behind the liquid-crystal panel. Most sets use either direct-lit or edge-lit LED strip assemblies — Samsung and LG typically employ 3 V or 6 V SMD LEDs on aluminium bars, while Sony and Philips often use local dimming zones with a dedicated driver for each zone. When even a single LED chip burns out, the driver detects an abnormal voltage drop across the strip and shuts down the entire bar or the whole backlight — the result is a black screen even though the TV continues to run in the background. Older models with CCFL (cold-cathode fluorescent) backlamps show a similar symptom when the inverter board fails to deliver the high-voltage drive signal. In our service centre we open the panel, use a multimeter and a dedicated LED tester to identify the defective diode or strip, and carry out a precise replacement while preserving uniform brightness. We always agree a firm estimate before any work begins, and if you decide not to proceed the TV goes back with no obligation. The unit must be brought in person during opening hours.

Likely causes

Individual LED chip burned out in the strip — The single most common fault — one or more SMD LEDs have failed, causing the driver protection circuit to shut down the entire strip or backlight zone.
LED driver board failure — A MOSFET or control IC on the power board or dedicated LED driver module has blown, and the driver can no longer supply stable constant-current power to the LED strips.
Edge-lit diffuser plate warped — In edge-lit sets the diffuser plate has warped or delaminated from heat, creating uneven light distribution or dark patches at the screen edges.
Backlight inverter failure (older CCFL TVs) — In CCFL-backlit models the inverter board fails to deliver the high-voltage pulse to the lamps — the screen flashes for an instant and then goes dark, or never lights at all.
LED strip solder joint cracked — Thermal cycling has cracked the solder joint between the LED strip and its power cable, causing intermittent or complete loss of contact.

What you can check yourself

Darken the room and display a bright white image — if you see uneven bright and dark patches, a LED strip is partially failed.
Turn the TV on in a pitch-dark room and shine a torch straight at the screen — if you can faintly see the menu or channel number, the mainboard and panel work but the backlight does not.
Check whether the TV switches on and then shuts off again after a few seconds — that points to the LED driver protection tripping.
Unplug the TV from the mains for 5 minutes and try again — a transient LED driver fault sometimes clears after a full power cycle.

When to bring it in

If after these checks the screen is still dark or unevenly lit, professional bench diagnostics are needed. We open the panel, test every strip and every LED individually with a dedicated LED tester, and measure the driver output voltage and current. Faulty LEDs or entire strips are replaced with a matching substitute, verified for brightness and colour temperature. All work carries a 3-month warranty. Bring the TV to Silmaču iela 6.

Fast on-site diagnostics. Repair warranty: 3 months.

Affected brands

Samsung LG Sony Philips TCL Hisense Toshiba Grundig Sharp

Frequently asked questions

Why customers choose SATER

From CRT to the latest Smart TVs. We repair televisions of every era — from tube sets to OLED and QLED.
LED backlight diagnostics on a professional test rig. We pinpoint the faulty LED strip without replacing the entire panel.
Samsung, LG, Sony parts in stock. Power boards, T-Con boards, LED drivers — key components always on the shelf.
30+ years of experience. The service centre has been operating since 1993.
We serve all of Latvia. Our service centre is in Riga and we accept devices from anywhere in the country.