A black, green or pink line running along the fold of a Z Flip or Z Fold is the flexible
display failing at the crease. It is not a software glitch and it does not heal. It almost always
spreads, and the fix is a screen replacement, not a repair of the line itself.
It usually starts small. A faint line along the fold that you only notice on a white background.
A week later it is darker. A month later half the screen is dead or the touch has stopped
responding on one side.
This is the most common way a folding phone fails, and it is worth understanding what is
actually happening inside, because it changes what you should do about it and how quickly.
What the line actually is
The inner display of a Z Flip or Z Fold is not a sheet of glass. It is a flexible OLED panel
built in layers, with ultra-thin glass or a polymer layer on top, bonded to a frame that bends
every time you close the phone.
Running through that panel are the driver traces that carry signal to each row of pixels. At the
crease, those traces bend with the phone. Thousands of folds, plus pressure, heat or moisture, and
eventually a trace fractures or the layers separate along the fold axis.
When that happens, every pixel served by the broken traces goes dark. Because the traces run in
a line, the failure appears as a line.
The line is not the problem. It is the symptom of a panel that has already begun to
fail.
Does it spread?
In our experience, yes, and usually faster than people expect. A fracture at the crease
concentrates stress on the traces next to it, so each fold makes the next failure more likely.
The typical progression looks like this:
still works everywhere.
unreliable along the fold.
stop responding to touch.
There is no reliable way to stop it once it has started. Closing the phone less does not reverse
the damage that is already there.
Can the line be repaired without replacing the screen?
No, and you should be cautious of anyone who says otherwise.
The break is inside a bonded, sealed display assembly. There is nothing to re-solder and nothing
to reseat. The panel, the digitiser and the protective layers are laminated into one unit, and on
most foldable models that unit is bonded to the frame as well.
The honest answer is that fixing the line means replacing the inner display assembly.
Is it the inner screen or the outer screen?
Almost always the inner one, because the outer cover screen does not bend.
This matters because they are separate parts at very different prices. If the line is on the
large screen you see when the phone is open, that is the inner display. If your damage is on the
small screen on the outside, that is the cover screen, and it is a different and usually cheaper
job.
What causes it in the first place
the panel at a single point. This is the most preventable cause we see.
contract at different rates, stressing the bond at the crease.
seal. Humidity and spills reach the panel edge there first.
reach the limit sooner, which is normal wear, not a defect.
exactly where the panel is weakest.
exposes the softest layer directly to fingernails and pressure.
Check the fold before you close the phone, especially at the beach, in a workshop, or after
the phone has been in a bag with keys or coins. A single piece of grit closed into the crease can
end a display that would otherwise have lasted years.
What a replacement costs
Inner display prices depend heavily on the model, because the panel itself is the expensive part
and each generation uses a different one. As a guide, inner screens run from RM850 for a Z Flip 1
up to RM2,550 for a Z Fold 7. Cover screens are considerably cheaper.
| Example | Inner screen |
|---|---|
| Galaxy Z Flip 1 | RM850 |
| Galaxy Z Flip 5 | RM1,280 |
| Galaxy Z Fold 4 | RM1,850 |
| Galaxy Z Fold 7 | RM2,550 |
Every model we handle is listed on the
foldable repair price page, inner and
cover, so you can check yours before you go anywhere.
When it is not worth repairing
We will say so. If the inner display on an older Fold costs close to what the phone is worth
used, replacing it is often the wrong call, and we would rather tell you that than take the job.
The calculation we run with customers is simple: the repair price against the phone’s realistic
remaining value and how much longer it will serve you. On newer models the repair almost always
wins, because the replacement phone costs several times the repair. On a Z Flip 1 with a tired
battery and a failing hinge, it often does not.
Frequently asked questions
No. The failure is physical, inside the display assembly. Software cannot restore pixels
that are no longer receiving signal. If a reset changes anything, the problem was something
else.
Sometimes, if the panel failed on its own within the warranty period and there is no sign of
impact, pressure or moisture. In practice most cases are assessed as accidental or
out-of-warranty damage. Check with Samsung first if your phone is still in warranty, because if
they cover it, that is the better outcome for you.
You can, but expect it to get worse, and expect the touch layer to fail along the line
before the display does. Back up your data now rather than later.
It depends on parts availability for your exact model. Some are stocked and some are
ordered. We confirm the realistic time when we quote, before any work starts.
A crease is normal on every foldable, new or repaired, because the panel bends. What should
not come back quickly is the line, provided the cause is addressed and no debris is trapped in
the fold.
Not sure whether the line is on the folding panel or the outer one? Our guide on inner screen versus cover screen walks through a three-question check you can do yourself.
Chamo is a gadget repair shop in Taman Puncak Jalil, Seri Kembangan, Malaysia, operating since
2014. This guide is based on foldable devices that come across our own bench, not compiled from
other websites.
The technical work is done by
Zaki, a Samsung Galaxy Flip and Fold repair
specialist. Our pricing and parts policy is set out on our
content policy page.
Not sure which screen is damaged?
Bring the phone in and we will check it first, at no charge, and tell you exactly what failed
and what it costs before any work begins.
