Lines 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 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 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 line comes from one of three places
Every line on a screen — vertical, horizontal, coloured, black, flickering or solid — starts in one of three places, and almost all of the confusion about them comes from not knowing which.
1. The panel. The glass itself has rows and columns of drivers. When one fails, the row or column it feeds stops working, and you get a line that is exactly one or a few pixels wide, perfectly straight, and completely fixed. It never moves, never flickers, and is there the instant the screen lights up.
2. The cable or connector. Between the panel and the board that drives it there is a ribbon cable. If it is worn, loose or corroded, the signal for whole groups of rows arrives damaged. That produces lines that come and go, change when the screen is moved, flicker, or appear in bands rather than as one clean line.
3. The graphics side. The chip or the driver software that generates the image can produce lines, tearing and distortion before the picture ever reaches the panel. These usually affect the whole image, often appear alongside artefacts elsewhere, and can change with what is on screen.
Everything below is about telling those three apart, because they have completely different costs.
The three checks that identify it, in order
Check 1 — does it survive an external screen? On a laptop, plug into a monitor or TV and mirror the display. If the external picture is clean, the fault is the laptop’s panel or its cable. If the same lines appear on the external screen, the panel is innocent and the problem is on the graphics side. On a desktop, unplug the video cable and leave the monitor on: if the line is still there on the "no signal" screen, it is inside the monitor.
Check 2 — is it there before the operating system loads? Watch the manufacturer’s logo at power-on, or enter the BIOS. A line visible at that moment is hardware, full stop — no driver update, no setting and no software will touch it. A line that only appears once Windows or macOS has started is very likely a driver or a display-setting problem, and those are free to fix.
Check 3 — does it change when you move things? Open and close the laptop lid slowly. Flex the video cable on a monitor. If the line appears, disappears, moves or changes colour as you do, you have found it: the cable. This is the single most useful test on a laptop and it costs nothing.
What the direction tells you
The direction of a line is a real clue, because rows and columns are driven by different hardware.
A vertical line usually means a column driver has failed, or the connection to one column of the panel has broken. On many panels the column drivers sit along the top or bottom edge, bonded to the glass, which is why vertical lines are so often permanent — that bonding is not a serviceable part.
A horizontal line usually points at a row driver or, more often on laptops, at the ribbon cable, because the cable carries row data and is the part that physically flexes. Horizontal lines that change with lid angle are the classic signature of a worn hinge cable.
Many lines together, or lines plus distortion is usually not a panel fault at all. That pattern points at the T-Con board on a monitor or television, or at the graphics chip.
Solid or flickering?
A solid, unchanging line that is the same on every image and present from the moment the screen turns on is a hardware break — in the panel or in its connection. It will not heal and it usually does not spread.
A flickering or intermittent line is a connection problem, and that is comparatively good news: a loose or worn cable is cheap. Reseat both ends of a monitor cable, try a different cable and a different port before assuming anything worse.
A line that grows, or gains company over weeks, is a failing panel edge or a failing T-Con board. Both get worse. If the machine is worth keeping, deal with it early rather than waiting.
Does the colour of the line mean anything?
Sometimes. A black line means those pixels receive nothing at all — a dead row or column. A white or bright line means they are stuck fully on. A coloured line — green, red, blue, pink — means one of the three subpixel channels is stuck or dead along that line, which is why green and pink lines are so common on OLED phone screens where each subpixel is driven individually.
What the colour does not tell you is whether it is fixable. A green line and a black line in the same position have the same prognosis. The colour narrows the electrical cause; the behaviour tests above decide the repair.
On a laptop: it is usually the hinge
A laptop’s display cable runs from the mainboard, through the hinge, to the panel, and it is folded and unfolded every single time the lid moves. After a few years of that, conductors crack and connectors loosen. This is why laptop lines behave in ways that desktop lines never do: appearing at a certain lid angle, vanishing when you press near the hinge, flickering as the screen opens.
Thin consumer laptops suffer most because their lids flex. HP Pavilion, 15s and Victus models use a thin eDP cable that runs through the left hinge and is a known wear point — lines and flicker that change with lid angle on those machines are the cable, not the panel. Lenovo IdeaPad models show a similar pattern.
The reason this matters is money: a display cable is one of the cheapest parts in a laptop, and a panel is one of the more expensive. Never accept a panel quote for a laptop until someone has ruled out the cable.
On a monitor: the T-Con board
Inside a desktop monitor, between the main board and the panel, sits the timing controller — the T-Con board. It turns the incoming video into the row and column signals the panel needs. When it fails you get wide bands, groups of lines, or a distorted image rather than one clean line.
Unlike the drivers bonded to the panel glass, the T-Con board is a real, replaceable component. On a large or high-refresh monitor it is genuinely worth quoting for, and a competent repairer can often fit one for far less than a new panel. That makes "many lines" on a monitor a better outcome than "one perfect line" — the first is often repairable, the second usually is not.
On a phone: the OLED driver
A green, pink or white line running down a phone screen is the classic OLED failure. It appears after a drop, after moisture, or sometimes on its own as the panel ages, and it is a break in the driver connection along the edge of the display.
It cannot be fixed by software, restarting or any app, whatever a video may claim. It typically widens over weeks. Because the display and digitiser are bonded on modern phones, the repair is a full display replacement.
One thing worth knowing: several makers have run extended service programmes for exactly this fault on specific models, because it appeared in large numbers with no impact involved. If your line appeared with no drop and no knock, check whether your model has such a programme before paying for a repair — and claim it while the phone is in warranty.
What you can actually try yourself
Not much, and it is worth being straight about that — but these four cost nothing and occasionally work:
Reseat and swap the video cable on a desktop. A failing HDMI or DisplayPort cable produces convincing lines and is the cheapest possible fix.
Try a different port on both the monitor and the computer.
Update, or roll back, the graphics driver. If the lines started after an update, roll back. If they started for no reason, update. Only relevant if the lines are absent in the BIOS.
Set the native resolution and refresh rate. A mismatched refresh rate can produce banding and tearing that looks like lines.
What not to do: do not press, tap or bend the panel. Videos suggesting you press near the line to "reseat" it are describing a technique for a loose ribbon inside the panel, and on any modern display the far likelier outcome is a cracked layer and a much worse screen.
What it costs to fix
On a laptop: a display cable is inexpensive and the labour is modest. A standard 1080p panel is a commodity part; touch, high-refresh and OLED panels cost several times more, and on some thin machines the panel comes bonded to the whole lid, which changes the price entirely. Ask which the quote covers.
On a monitor: a T-Con or power board replacement is often worth doing. A panel replacement usually is not — the panel is most of the monitor’s value, so on anything under about 27 inches a new monitor is generally the better buy.
On a phone: display and digitiser replace as one unit, so any line means a full display replacement.
On a television: wide bands and distortion often trace to the T-Con board and are worth quoting. A single thin fixed line is usually a panel fault, and a TV panel is not economically replaceable.
Warranty
A line that appeared with no drop, no knock and no liquid is a hardware failure and is covered while the device is in warranty. Makers do sometimes argue; what settles it is evidence. Photograph the line on a white screen and on a black screen, note the date, and note that there is no physical damage to the device.
A line that appeared immediately after an impact is accidental damage and is not covered by a standard warranty, even if the outside looks perfect — a knock can crack the panel’s bonded driver edge without marking the case at all.
Dead-pixel thresholds do not apply here. A line is a driver or connection failure, not a pixel count, and is treated as a straightforward fault.
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
Why is there a line on my computer screen?
It is a failed row or column driver in the panel, a worn or loose display cable, or a graphics problem. 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. On a laptop, connect an external screen — a clean external picture means the laptop panel or its cable is at fault.
Can lines on a screen be fixed?
A line caused by a loose or worn cable can be fixed cheaply, and on a monitor a failed T-Con board is genuinely replaceable. A line caused by a failed driver bonded to the panel glass cannot be repaired and needs a new panel. The tests above tell you which you have.
What does a vertical line mean versus a horizontal one?
A vertical line usually means a failed column driver, which is often bonded to the panel and not repairable. A horizontal line more often means a row driver or, on a laptop, the ribbon cable through the hinge — which is a cheap repair. Many lines together usually mean the T-Con board or the graphics chip rather than the panel.
Why do lines appear when I move my laptop lid?
That is the display cable at the hinge. It flexes every time the lid opens and eventually the conductors crack. It is one of the cheapest laptop repairs and does not need a new panel. Never accept a panel quote before the cable has been ruled out.
Will pressing on the screen fix a line?
No, and it is the most damaging advice on the internet. Pressing may briefly change the line, which feels like progress, but on a modern bonded display the likely result is a cracked layer and a permanently worse screen.
Is a green or pink line on a phone screen repairable?
Not by software. It is a break in the OLED driver connection and it usually widens over time. The repair is a display replacement. If it appeared with no drop or knock, check whether your model has an extended service programme — several makers have run them for this exact fault.
Is a screen line covered by warranty?
Yes if it appeared with no impact and no liquid, while the device is in warranty — it is a straightforward hardware failure and dead-pixel thresholds do not apply. No if it followed a drop, even when the case is unmarked, because a knock can crack the panel’s driver edge without leaving a visible mark.
Related
Also free on Toolsitz: Screen Test Tool — no login.