The two-second test that halves the problem list
Open the TV’s own menu (Settings, or the Home screen). Now look at the lines:
- **Lines appear over the menu too** — the fault is inside the TV: the timing-control board, a ribbon connection, or the panel itself
- **Lines vanish in the menu** — the fault is upstream: the source device, the cable, or the input board’s processing of that signal
This works because the menu is generated by the TV itself — if the menu renders clean, the panel and its timing hardware can draw a perfect image, and the lines come from whatever feeds it.
If the lines are upstream: the free fixes
Lines that disappear in the menu are the good case:
- Swap the HDMI cable — cables fail more often than anything else in the chain
- Try a different input (another HDMI port, or a streaming app built into the TV)
- Test the same source on another TV if you have one
- Reseat the cable at both ends — partially seated HDMI connectors cause exactly this symptom
If the lines are in the menu: the board story
Lines present over the TV’s own menu point at the internal image chain. The classic pattern for **vertical lines on one side of the screen** is the timing controller — the T-Con board — or the flat ribbon cables that carry the image data from it to the panel.
The T-Con is a small board mounted directly behind the panel. When it fails — from heat, age, or a surge — the lines are typically fixed in position, don’t move, and often worsen over weeks. The good news: on most models the T-Con and its cables are a $38–60 part, and the repair is routine for any shop.
The bad news: the same symptom can also mean the **panel itself** is failing, which is usually the end of the TV’s economic life. Telling a $50 T-Con fault from a dead panel requires either opening the set or experience with the pattern — this is the single most valuable thing a photo diagnostic settles before you commit to a repair.
Reseating the panel’s ribbon cables is sometimes suggested online. On most modern TVs those connectors are fragile, bonded to the panel glass, and a slipped reseat turns a $50 repair into a panel replacement. We don’t recommend it as a DIY step.
What the repair usually costs
Typical US numbers for the T-Con case: the board runs $38–60 depending on the model, plus $60–100 labor — call it $98–160 all-in. The panel case: a replacement panel usually costs more than the TV is worth, which is why the honest answer there is usually "replace the TV."
Lines that are fixed in position and getting worse is the classic T-Con signature — and the pattern is readable from photos. A $25 diagnostic names the likely part and the realistic cost, so you can decide before paying a shop to open the TV.
Get a $25 diagnosticCommon questions
Why do the lines get worse over time?
A failing T-Con board or its ribbon connections degrade progressively — heat cycles and oxidation widen the fault. Lines that appear suddenly and stay identical point more at a connection or a source problem; lines that spread or multiply over weeks point at hardware that’s actively failing.
Can a software update or reset fix vertical lines?
No. Lines are a physical signal-path or panel issue — the image data is corrupted on its way to the pixels, not in the software. A factory reset is worth two minutes only because it rules out the rare firmware-graphics fault, but expect no change.
Is a TV with lines repairable, or should I replace it?
If it’s the T-Con board or a cable, repairable — typically for $100–160. If it’s the panel, replacement is usually the honest answer. The diagnostic report states which case the evidence supports and what the repair would cost, so the decision is arithmetic.