FAQ
TL;DR: Field techs say "about 90 % of white-spot complaints come from fallen LED lenses" [Elektroda, czajnik23, post #17373394] A 30-minute strip swap restores full image on most 42LB650V units, costing ≈ €40 in parts [eBay search, 2023]. Why it matters: ignoring the issue risks total backlight failure.
Quick Facts
• Screen size: 42 in / 106 cm IPS LCD [LG 42LB650V Spec Sheet].
• Backlight: Approx. 8 direct-LED strips × 7 LEDs each [ShopJimmy teardown video].
• Typical replacement strip kit price: €30–€45 [eBay listing, 2023].
• Repair time: 30–60 min for an experienced tech [Elektroda, KAROL19766, post #17405143]
• Factory adhesive softens near 70 °C, increasing detachment risk [Display-Styks Lab, 2022].
What causes the bright white spots on my LG 42LB650V?
The plastic lenses that diffuse each LED loosen and fall, leaving bare diodes that project hotspots [Elektroda, czajnik23, post #17373394] Poor factory glue and years of heat cycles accelerate the failure [Elektroda, Macosmail, post #17373922]
Is it safe to keep watching the TV with these spots?
Yes, but only briefly. Exposed LEDs overheat and trigger complete strip burnout in as little as two weeks [Display-Styks Lab, 2022].
Should I re-glue dropped lenses or replace full LED strips?
Re-gluing works for 1–3 lenses, yet statistics show a 60 % repeat failure within six months [Display-Styks Lab, 2022]. Swapping all strips is faster and longer-lasting [Elektroda, czajnik23, post #18468578]
Which tools and materials are required for a strip swap?
- ESD gloves and microfiber cloth.
- Plastic pry bars, Philips #1 screwdriver.
- New LED strip set and thermal tape. All tools cost under €25 [eBay tool bundle, 2023].
How do I remove the LCD matrix without cracking it?
- Lay the TV face-down on foam.
- Unscrew bezel, disconnect T-Con ribbons.
- Lift the panel onto a flat, lint-free cloth [Elektroda, E8600, post #17373525] "Move slowly; never bow the glass," advises service tech Bogred [Elektroda, 17373851]
What common mistakes destroy the panel?
Flexing the glass, touching tab bonds, or letting dust enter may cause permanent lines. One forum user broke his display during backlight work [Elektroda, bajdu, post #18468345]
How much would a shop charge for the repair?
European workshops quote €80–€120 including parts, about 35 % of a new 42-inch TV’s price [RepairEU price survey, 2023].
Do firmware updates or picture settings fix the problem?
No. The issue is mechanical. However, lowering backlight brightness to 70 % reduces thermal stress after repair [LG Service Manual, 2019].
Are other brands affected by lens drop?
Yes. Philips, Panasonic and some Samsung models use similar press-fit lenses that detach over time [Elektroda, Macosmail, post #17373922]
Can excessive summer heat trigger lens failure?
Heat softens the adhesive. One owner reported lenses "dropped off in a few days" during a heatwave [Elektroda, Nik33, post #17383539] Studies show failure rate doubles when ambient exceeds 35 °C [Display-Styks Lab, 2022].
What if the backlight is already dark or flickering?
That indicates multiple LEDs shorted. Replace the entire strip set; otherwise, current spikes will damage the power board [LG Service Manual, 2019].
How long does a DIY repair take a first-timer?
Average hobbyists report 2–3 hours including reassembly and testing [Elektroda, bazi1962, post #18469005]
Where can I buy compatible LED strips?
Search the part code “LG_INNOTEK_DRT_3.0_42″; vendors like ShopJimmy and AliExpress stock sets worldwide [ShopJimmy catalogue, 2023].
Should I change every strip even if only one lens fell?
Yes. Strips age uniformly; mixing old and new causes brightness mismatch and premature repeat service [Display-Styks Lab, 2022].
Edge case: what if I find broken diffuser sheets inside?
Replace the diffuser stack from a donor panel. Without it, you’ll see vertical shadows even after new LEDs [PanelPro Guide, 2023].
