Black line on screen
A line pattern shows a missing or extra row instantly; the colour tiles below show whether it is on every colour.
Plain colours, full screen:
A black line on a screen screen is either the signal or the panel.
Test it now
Full-screen white, then black, then the colours: a panel line is fixed on all of them. Take a screenshot — a line that is in the screenshot is the graphics card or driver. Swap the cable (HDMI/DisplayPort) and the port. On a TV, open the TV's own menu: lines across the menu are the panel or T-con board.
What it is
A black line on a screen screen is either the signal or the panel. Lines that appear in a screenshot, or that change when you swap the cable or the port, are the graphics card or cable. Lines that are fixed on every input and every colour are the panel's driver board or the panel itself.
Can it be fixed?
Cable: yes, a small repair (the cable is a ₹500–1,500 part in India, $20–40 in the US, plus labour). Graphics driver: yes, free — update, or roll back. Panel: no, replace the panel. Graphics chip hardware: usually a motherboard, and on a laptop that decides whether it is worth it.
What to do
- Screenshot: line in it = graphics card or driver.
- Swap cable and port; try another source.
- Lines on every input and in the on-screen menu = panel or driver board; get a quote.
- Compare the quote to a new screen — for monitors under 27" a new one is usually cheaper.
What a repair costs
| United States | Phone display $80–380; laptop panel $100–300; monitor panel from $150 (often more than a new monitor) |
|---|---|
| India | Phone display ₹2,000–20,000; laptop panel ₹3,000–15,000; monitor panel ₹4,000–10,000 (a new monitor is often the better buy) |
Typical ranges from repair-shop and manufacturer price lists, 2026-09-06. Get two quotes; prices vary by model and city.
Warranty
Most makers replace a panel under warranty for physical panel faults that are not accidental damage; pressure marks, cracks and liquid damage are treated as accidental and are not covered. For dead pixels, each brand has a threshold (typically 3–5 bright or 5–8 dark pixels on a laptop; Dell's premium-panel guarantee replaces at one bright pixel).
A black line means a row or column is receiving nothing
Every panel is driven as a grid: drivers along one edge feed the columns, drivers along another feed the rows. A black line — as opposed to a white or coloured one — means the pixels along that line are getting no signal at all. The connection is broken rather than stuck.
That matters for the prognosis, because a broken connection is either in the cable, which is cheap, or bonded to the panel glass, which is not.
Vertical or horizontal changes the odds
A vertical black line usually means a failed column driver. On most panels the column drivers are bonded directly to the glass along the top or bottom edge, and that bonding is not a serviceable part. Vertical black lines are therefore usually permanent and usually mean a new panel.
A horizontal black line more often involves the row drivers or, on a laptop, the ribbon cable that flexes through the hinge. That makes horizontal lines the more hopeful case: a display cable is one of the cheapest parts in a laptop.
This is a tendency, not a law — but it is the right place to start, and it tells you which quote to ask for.
The three tests
Move the lid. On a laptop, open and close the screen slowly. A line that appears, disappears or shifts is the hinge cable. Nothing else behaves that way.
Check before the operating system loads. If the line is on the manufacturer’s logo at power-on, it is hardware and no driver or setting will help.
Use an external screen. On a laptop, a clean external picture confirms the fault is the panel or its cable. On a desktop, unplug the video cable and leave the monitor on — if the line is still there on the empty "no signal" screen, it is inside the monitor.
Brand patterns worth knowing
Some machines fail in known ways, and naming them saves money.
HP Pavilion, 15s and Victus use a thin eDP display cable routed through the left hinge that wears with use. Lines and flicker that change with lid angle on those models are the cable.
Lenovo IdeaPad models show the same pattern.
MacBook Pro models have had a known fault producing black bands along the bottom of the display, related to the display cable and its routing. If you have black lines specifically along the bottom edge of a MacBook Pro, look up whether your model was covered by a service programme before paying for anything.
What it costs
On a laptop: a display cable is inexpensive and quick. A panel is a commodity part unless it is touch, high-refresh, OLED, or bonded into the lid — ask which the quote covers.
On a monitor: if it is one clean line, the driver is on the glass and the panel is finished, which usually means a new monitor. If it is bands or many lines, suspect the T-Con board, which is a real replaceable part and worth quoting.
On a phone: a display replacement, because the panel and digitiser are one unit.
What not to do
Do not press, tap or bend the panel near the line. Videos suggesting you "massage" a line away are describing a loose internal ribbon on old displays; on a modern bonded panel the far likelier result is a cracked layer and a much worse screen. Nothing you can do from the outside reconnects a broken driver.
What a repair costs
United States: Phone display $80–380; laptop panel $100–300; monitor panel from $150 (often more than a new monitor)
India: Phone display ₹2,000–20,000; laptop panel ₹3,000–15,000; monitor panel ₹4,000–10,000 (a new monitor is often the better buy)
Warranty
Most makers replace a panel under warranty for physical panel faults that are not accidental damage; pressure marks, cracks and liquid damage are treated as accidental and are not covered. For dead pixels, each brand has a threshold (typically 3–5 bright or 5–8 dark pixels on a laptop; Dell's premium-panel guarantee replaces at one bright pixel).
Frequently asked questions
What causes a black line on a laptop screen?
A row or column of pixels receiving no signal — either a failed driver bonded to the panel, or a broken display cable. Open and close the lid slowly: a line that changes is the cable at the hinge, which is a cheap repair.
Is a vertical black line different from a horizontal one?
Usually. A vertical line points at a failed column driver bonded to the panel glass, which is not repairable. A horizontal line more often involves the row drivers or the laptop display cable, which is cheap to replace.
Can a black line on a screen be fixed?
If the cause is the display cable, yes and cheaply. If a driver bonded to the panel has failed, no — the panel needs replacing. The lid-movement test and an external screen tell you which you have.
Will pressing the screen fix a black line?
No. On a modern bonded display, pressing is far more likely to crack a layer than to reconnect anything. It is the most damaging advice online about screen lines.
Why does my MacBook Pro have black lines along the bottom?
That is a known pattern related to the display cable and its routing, and some models were covered by a service programme. Check whether yours was before paying for a repair.
Related
Also free on Toolsitz: Screen Test Tool — no login.