Vertical or horizontal lines on a phone screen can appear suddenly, after a drop, following liquid exposure or sometimes with no obvious damage at all. The colour, position and behaviour of the lines can provide useful clues about what has gone wrong.
Persistent lines are often caused by a problem within the display itself, particularly after impact damage. But software faults, liquid damage, internal connections and other issues can sometimes produce similar symptoms, so the appearance of lines alone does not identify the exact fault.
FoneFix Honiton diagnoses phone display problems for customers across Honiton and East Devon, including iPhone, Samsung Galaxy and Google Pixel.
Where the lines are, when they appeared and whether they change.
The appearance of the lines can give useful clues, but colour alone doesn't diagnose the fault. Pay attention to whether the lines are vertical or horizontal, whether they stay in exactly the same place, and what happened immediately before they appeared.
One or more vertical lines that remain in exactly the same position can point towards a fault within the display assembly. They are particularly significant if they appeared immediately after the phone was dropped, bent or subjected to pressure.
Key clue: the line stays fixed in the same placeHorizontal bands, thin lines or sections of distortion can also indicate a display problem. If they remain visible during startup and across different apps and screens, a problem with the display hardware becomes more likely.
Key clue: visible throughout normal phone useA bright green vertical line is a symptom sometimes seen on OLED displays. It can appear after physical damage, develop with a failing display or occasionally appear without an obvious crack in the outer glass.
Key clue: bright, narrow and often permanently visibleLines are not always green. White, pink, purple, blue or mixed coloured lines can occur when part of the display is no longer producing the image correctly. The colour itself is less important than whether the line is persistent and fixed.
Key clue: colour does not identify the exact failed partSeveral lines appearing together, especially with black patches, flickering, discolouration or areas where the image has disappeared, can indicate more extensive damage within the screen assembly.
Key clue: additional display symptoms appear alongside the linesA line that appears briefly and disappears after restarting may have a different cause from a line that remains in exactly the same position every time the phone is switched on. That behaviour is often more useful diagnostically than the colour of the line itself.
Lines on a phone screen can come from several different types of fault. Some are temporary, while others point more strongly towards damage within the display itself.
A drop can damage the internal display even when the outer glass looks almost perfect. Vertical or horizontal lines may appear immediately, or they can develop later as the damaged screen deteriorates.
The display panel itself can develop a fault even without an obvious recent impact. A single bright line, several fixed lines or areas of distortion can indicate that part of the screen is no longer producing the image correctly.
Phones do not need to be dropped to damage a display. Pressure in a pocket, sitting on the phone, bending the chassis or twisting the device can place stress on the screen and create internal display faults.
Liquid can affect the display, internal connectors or surrounding circuitry. The result may be lines, flickering, discolouration, intermittent picture loss or several symptoms appearing together.
A poor or damaged internal connection can sometimes create display symptoms that look similar to a failed screen. This is more likely if the phone has previously been repaired, opened or suffered an impact.
Not every line is caused by broken hardware. A temporary software, graphics or app-related issue can occasionally create unusual display artefacts that disappear after restarting the phone.
If a phone has had a screen replacement before, lines can sometimes be linked to the replacement display itself, damage to the new screen or an issue that needs checking around the installation.
A permanent line after a drop is very different from a graphical glitch that vanishes after restarting. That is why the history of the fault is just as important as the appearance of the screen.
If lines appeared shortly after the phone was dropped, knocked or crushed, physical screen damage becomes much more likely — even if the outer glass still looks intact.
A phone display is made from several layers. When the phone is dropped, the force can pass through the outer glass and damage the OLED or LCD underneath without leaving a visible crack.
If part of the display panel is damaged, the affected area may stop producing the image correctly. That can result in a single line, several coloured lines or larger sections of distortion.
Sometimes the display works normally straight after a drop and develops lines later. A damaged screen can deteriorate gradually, especially if the phone continues to be used or subjected to pressure.
If lines started after a drop and remain visible after restarting the phone, the display itself is usually a much stronger suspect than a temporary software issue.
If lines have appeared on your phone screen, a few simple checks can help establish whether you are seeing a temporary software problem or something more likely to involve the display itself.
A restart is the simplest way to rule out a temporary software or graphics glitch. Switch the phone off normally if possible, then turn it back on and check whether the lines return.
If the lines disappear completely, software becomes more plausible. If exactly the same lines immediately return, a display fault becomes more likely.
Look at the Home Screen, Settings and several different apps. If the lines stay in exactly the same position regardless of what is being displayed, that is useful diagnostic information.
A fixed line visible across different screens and apps points more strongly towards the display than a problem that appears only inside one particular app.
Look for black patches, flickering, discolouration, image distortion or areas where the picture has disappeared. Also check whether the touchscreen still responds normally.
Lines accompanied by other display problems make physical screen damage or display failure more likely.
Think about whether the phone was recently dropped, knocked, bent, exposed to pressure or got wet. Also consider whether the screen has previously been replaced.
The timing matters. Lines appearing soon after impact, liquid exposure or a previous repair provide a much stronger clue than the colour of the lines alone.
A single line may remain unchanged, but damaged displays can also deteriorate. Watch for additional lines, spreading black areas, increasing flicker or sections of the screen becoming unusable.
A display fault that is spreading or becoming less usable is unlikely to be solved by repeatedly restarting or changing settings.
Avoid pressing hard on the display, twisting the phone or bending it to see whether the lines change. If the display is already damaged, doing this can make the fault considerably worse.
If the same lines remain in the same position after restarting and appear throughout normal phone use, there is little benefit in repeatedly changing software settings. At that point, identifying whether the display or another internal component is responsible is more useful.
The underlying causes are broadly similar across modern smartphones, but the type of display fitted and the history of the fault can make certain symptoms more useful on some devices than others.
On iPhones, fixed vertical or horizontal lines often point towards a problem within the display assembly, particularly if they appeared after a drop, impact or pressure on the phone.
Many Samsung Galaxy models use OLED displays, where a narrow green, white, pink or other coloured line can sometimes appear when part of the display panel develops a fault.
Google Pixel displays can also develop fixed coloured lines, sections of distortion or other display faults following impact damage or failure within the screen assembly.
A fixed line after impact, a line that changes after restarting and several lines appearing alongside black areas are all different symptoms. The behaviour of the display and what happened before the fault appeared are usually more useful than the logo on the phone.
FoneFix Honiton repairs iPhone, Samsung Galaxy, Google Pixel and other smartphones for customers from Honiton, Axminster, Sidmouth, Seaton, Ottery St Mary, Cranbrook, Cullompton and across East Devon.
Not always. Persistent lines are often linked to a fault within the display assembly, but software problems, internal connections, liquid damage and previous repairs can sometimes produce similar symptoms.
On many modern phones, the OLED or LCD panel is part of a complete display assembly. If that panel is damaged, replacing the screen assembly is usually the practical repair.
Replacing a screen without establishing the cause can mean replacing a perfectly good display while the actual fault remains elsewhere.
Fixed, intermittent, vertical, horizontal or spreading?
Drop, liquid, pressure, previous repair or no obvious cause?
Establish whether the display or something else is responsible.
We do not simply replace the screen because lines are visible. We establish whether the display itself has failed, whether the fault followed impact or liquid damage, or whether another issue needs investigating before recommending the repair.
Yes, they can. Some screen faults stay almost unchanged for weeks or months, while others gradually spread, develop additional lines or cause larger areas of the display to stop working.
Internal display damage can worsen gradually. A phone may begin with one thin line and later develop additional lines, flickering, black patches or areas where the image disappears completely.
A single vertical or horizontal line may remain stable, but a failing display can develop additional lines over time.
Dark areas can indicate that sections of the display are no longer producing an image. These areas may expand after impact damage.
Lines combined with increasing flicker or intermittent image loss are a stronger sign that the display is deteriorating.
The picture and touchscreen are separate functions, but damage affecting the screen assembly can eventually cause problems with both.
A lifting display can have several causes, including a swollen battery. Avoid squeezing, bending or forcing the screen back into position and have the phone inspected instead.
Even if the display continues working today, a damaged screen can become harder to use without much warning. Keeping an up-to-date backup means a worsening display problem is much less disruptive.
If the lines are persistent, appeared after damage or are being joined by other display problems, professional diagnosis becomes much more useful than repeatedly changing settings or restarting the phone.
If the lines appeared briefly, vanished after a restart and have not returned, a temporary graphical or software problem is possible.
A fixed vertical or horizontal line that remains visible across different apps and returns every time the phone starts is much less likely to be a random one-off glitch.
Lines combined with black areas, flickering, image loss, touch failure or damage after a drop are strong reasons to have the phone inspected.
These symptoms make a hardware or display fault more likely and can indicate that the problem is progressing.
If your phone has lines on the screen, we look at how the fault behaves, whether the device has been dropped or exposed to liquid, and whether the display itself is actually responsible before recommending a screen replacement.
That means you are not paying for a part simply because the symptom happens to look like a screen fault.
Display symptoms checked first
Repair history and damage considered
Screen replacement only when justified
FoneFix Honiton provides in-house phone and tablet repairs for customers across Honiton and surrounding East Devon, with over 15 years of repair experience.
Quick answers to some of the most common questions about vertical, horizontal and coloured lines appearing on a phone display.
Sudden lines can be caused by display damage, a failing OLED or LCD panel, liquid exposure, an internal connection problem or occasionally a temporary software or graphics glitch.
Persistent vertical lines are commonly associated with a display panel fault or physical damage, particularly if the same line remains in exactly the same position across different apps and after restarting.
Horizontal lines can also result from screen damage or display failure. If they appear everywhere on the phone rather than only within one app, a hardware issue becomes more likely.
A fixed green line can be a symptom of an OLED display fault or damage within the screen assembly. The colour alone cannot identify the exact cause, so the behaviour of the line is more useful diagnostically.
Yes. The outer glass can remain intact while the OLED or LCD display underneath is damaged. This is particularly common after an impact, bending or heavy pressure on the phone.
Yes. The force of a drop can travel through the screen assembly and damage the display underneath without shattering the cover glass.
It can. Liquid can affect the display, its connections or other internal circuitry and may cause lines, flickering, discolouration or intermittent image loss.
Occasionally. A temporary software or graphics problem can create visual artefacts, but persistent fixed lines that remain after restarting are more suggestive of a display-related fault.
If the problem is a temporary software glitch, restarting may clear it. If the same line immediately returns in the same position, restarting repeatedly is unlikely to fix the underlying problem.
Yes. Some remain stable, while others develop additional lines, black areas, flickering or sections of the display that stop working.
Not automatically. A damaged display often does require screen replacement, but software issues, internal connections, liquid damage and previous repairs can sometimes create similar symptoms.
If the lines are being caused by a failed or damaged display panel, replacing the screen assembly should resolve the problem. Proper diagnosis first helps confirm that the screen is actually responsible.
Persistent vertical, horizontal or coloured lines usually deserve a proper look — especially if they appeared after a drop, liquid exposure or alongside flickering, black areas or touch problems.
At FoneFix Honiton, we diagnose the fault first and only recommend a screen replacement when the display is actually responsible.
Monday–Friday 10:00am–4:00pm
Saturday 10:00am–2:00pm
Customers visit FoneFix from Honiton, Axminster, Sidmouth, Seaton, Ottery St Mary, Cranbrook, Cullompton, Chard and surrounding areas.