Pixelfehler

A bright dot that will not go away, or a black spot in the middle of the picture: pixel defects are immediately noticeable and reduce the value of monitors, notebooks and tablets. How many are permissible is regulated by the ISO 9241-307 standard via pixel defect classes. Here you will learn which defect types exist and what they mean for grading and resale.

What pixel defects are there?

A pixel of a color display consists of three subpixels in red, green and blue. If an entire pixel or a single subpixel fails, a pixel defect occurs.

Defect type	Appearance	Colloquially
Type 1	Pixel is permanently lit, visible as a white dot on a dark background	"Hot pixel"
Type 2	Pixel stays permanently dark, visible as a black dot on a light background	"Dead pixel"
Type 3	A single subpixel is permanently on or off, the dot appears colored	"Stuck pixel" or subpixel defect

If several defects are close together, this is called a cluster. There are limits for this as well.

Pixel defect classes under ISO 9241-307

ISO 9241-307 replaced the older standard ISO 13406-2 in 2008. It defines pixel defect classes from 0 to 3. For each class, it specifies how many defects of each type per million pixels are permissible at most. Class 0 means: not a single pixel defect. As the class rises, more defects are allowed. Compared with the old standard, the limits were tightened.

Manufacturers usually state their own pixel defect policy in their warranty terms, which is based on these classes but may deviate. Whether a display with a single defect is a warranty case therefore depends on the manufacturer.

Pixel defects on used devices

• Inspection: During refurbishment, displays are checked with single-color test images. The result is included in the test report .
• Rating: Pixel defects lower the Grading the condition grade and thus the resale value.
• Repair: If the defect is disturbing, the display or panel can be replaced. Whether this is worthwhile depends on the device.
• Distinction: A permanently visible ghost image is not a pixel defect but Burn-in (screen burn-in). Dust or pressure marks can look similar.

What matters when selling used notebooks and monitors is described in the article Notebook buyback and monitor sales.

Pixel defects and Second IT

Second IT inspects purchased devices and documents their condition. Defective displays are repaired in our own repair shop using original or certified replacement parts, and every repair ends with comprehensive functional tests. This raises the resale value, and the devices go into their second life cycle tested. More on repair of IT hardware.

Frequently asked questions about pixel defects

What does pixel defect class 0 mean?

A display of class 0 under ISO 9241-307 may not have a single pixel defect. Higher classes allow a limited number of defects per million pixels.

Can pixel defects be fixed yourself?

A stuck subpixel sometimes recovers after prolonged operation. Permanently dark or bright pixels generally cannot be repaired. Then the only remedy is replacing the display.

Are pixel defects a warranty case?

The manufacturer regulates this in its pixel defect policy. Many manufacturers accept a certain number of defects before replacing the device. The conditions for the specific model are decisive.

What is the difference between a pixel defect and burn-in?

A pixel defect is a permanently defective individual pixel that stays bright, dark or colored. Burn-in, by contrast, is a permanently visible ghost image caused by static content displayed for a long time. Dust or pressure marks can look similar to both.

How do pixel defects affect the resale value?

Pixel defects lower the condition grade in grading and thus the resale value. Inspection is done with single-color test images, and the result is included in the inspection report. Whether replacing the display is worthwhile depends on the device.