Dark spots, uneven backlight and clouding on a TV screen — repair in Riga

Likely causes

• Failed LED bar in a direct-lit array — A single bar failure in direct-lit TVs creates a visible dark zone on one side of the screen — we replace the bar and recalibrate current across the others for even brightness.
• Edge-lit backlight LED burnout — In edge-lit models, burnt LEDs cause a dark corner or vignette — usually the whole side LED strip needs replacing.
• Diffuser sheet warp or separation — Humidity makes the plastic diffuser sheet bow or delaminate from the light guide, producing bright clouds and general unevenness across the screen.
• Pressure damage to the LCD layer from packing or impact — Bad packing during transport or an object pressed into the screen leaves permanent dark marks directly on the panel — this is a panel-side failure.
• OLED compensation IC degradation — In older OLED sets the compensation chip no longer levels out pixel aging accurately, creating uneven brightness across the whole screen.
• Dust ingress onto the light-guide plate — Over years, dust finds its way inside the TV and settles on the light guide, producing blurred dark patches — a careful clean restores uniformity.

Try this first

1. Play a solid grey or white test pattern from YouTube (search "TV backlight test pattern") and watch the screen in a fully darkened room.
2. Turn off all room lights and compare the centre of the screen with the corners — uneven edge brightness points to an edge-lit fault.
3. Photograph the screen showing the test pattern — phone cameras often exaggerate defects the eye misses and help with diagnosis later.
4. Check whether the spots appear on several input sources (HDMI, USB, network) — if they do, the fault is inside the TV, not in the signal.

When to bring it in

Brands we repair

FAQ