Possible technical reason for green line pink line issue in Samsung phone

[Swatit394]

I don't have access to Samsung software code else I would have given exact reason why samsung phone display are getting vertical green line pink line issue after software update.

The vertical green and pink line issues that some Samsung phone users have experienced after a software update are typically related to display or GPU (Graphics Processing Unit) anomalies. This issue has been observed on OLED screens, which are commonly used in Samsung devices. Below, I’ll provide a detailed explanation, including a hypothetical example with technical details.

1. Understanding the Issue:

a. Display Technology:

 - OLED Panels: Samsung smartphones often use OLED (Organic Light-Emitting Diode) displays, which are prone to certain types of failure if not properly calibrated.

 - Pixel Addressing: The display screen is composed of millions of pixels, each of which can be individually controlled. A malfunction can cause a single row or column of pixels to display incorrectly, leading to the appearance of vertical lines.

b. Software Update Impact:

 - Driver Updates: Security updates often include updates to the GPU drivers or display drivers. A poorly optimized or incompatible driver update can cause communication issues between the software and the hardware.

 - Color Management: Software updates might also tweak the color management system or gamma correction algorithms, which could lead to incorrect voltage being supplied to certain rows or columns, causing them to display a solid color like green or pink.

2. Technical Cause:

a. Voltage Irregularities:

 - The display driver IC (DDIC) controls the display’s pixel rows and columns. If a software update changes how this chip manages voltage distribution across the screen, it can lead to permanent pixel damage or temporary malfunction. 

 Here’s a simplified code snippet in C-like pseudo-code, illustrating how the driver might control the voltage:

 ```c

 // Hypothetical function to set voltage for display rows/columns

 void setPixelVoltage(int row, int col, int voltage) {

 if (voltage > MAX_VOLTAGE) {

 // Over-voltage might permanently damage pixels

 displayMatrix[row][col] = COLOR_GREEN; // Incorrect voltage might cause green line

 } else if (voltage < MIN_VOLTAGE) {

 // Under-voltage might cause dim or unresponsive pixels

 displayMatrix[row][col] = COLOR_BLACK;

 } else {

 displayMatrix[row][col] = fetchColorData(row, col); // Normal operation

 }

 }

 // During an update, an incorrect voltage might be set for some rows/columns:

 void updateDriverFirmware() {

 for (int row = 0; row < TOTAL_ROWS; row++) {

 for (int col = 0; col < TOTAL_COLS; col++) {

 int newVoltage = fetchUpdatedVoltage(row, col);

 setPixelVoltage(row, col, newVoltage);

 }

 }

 }

 ```

b. GPU Overload or Miscommunication:

 - If a security update incorrectly alters the way the GPU processes display commands, the result could be a miscommunication between the GPU and the display hardware. For instance, if a line of pixels isn’t refreshed correctly, it could lead to them being stuck on a particular color.

 Consider the following simplified example, where the GPU sends display data:

 ```c

 void refreshDisplay() {

 for (int row = 0; row < SCREEN_HEIGHT; row++) {

 for (int col = 0; col < SCREEN_WIDTH; col++) {

 PixelData data = fetchPixelData(row, col);

 if (data.needsUpdate) {

 sendToDisplay(row, col, data);

 } else {

 // Issue: Skip update due to bug, might result in stuck line

 continue;

 }

 }

 }

 }

 ```

3. Real-World Example:

One real-world example is the Samsung Galaxy S20 series, where users reported vertical green or pink lines appearing after a software update. The lines often appeared randomly and were sometimes resolved by rolling back the update or replacing the display.

Example Scenario:

- A user updates their Samsung Galaxy S20 with the latest security patch. 

- After the update, a pink vertical line appears on the screen. The issue might have been caused by the software improperly adjusting the voltage for the OLED pixels along that line, leading to a constant display of pink.

- Upon reverting to an older firmware, the issue persists, indicating potential permanent damage to the display.

4. Conclusion:

The vertical green and pink line issue on Samsung devices post-software update can be attributed to a combination of hardware and software factors. The software update might inadvertently change how the display’s voltage is regulated or how the GPU communicates with the display hardware, leading to these issues. While some of these problems may be temporary and can be fixed with a software rollback, others might cause permanent damage to the display.

[puneet_me2006]

Whatever the exact root cause is Samsung understand it better & must accept that with software updates resulting in display issues dissatisfied consumer base is increasing day by day & they are doing nothing to act actively & proactively except some minor relief to premium series users.
Irrespective of consumer and warranty status they must understand that issue is spread to A,M,F series also and user is not responsible even if device is outside warranty because it's Samsung who has promised years of OS & SMC updates and has pushed it to devices post which the issues are spreading like wildfire.
All consumers of any series have paid the asking price and have buyed a package of 1 year hardware warranty + promised years of software experience.
If faulty software is causing hardware malfunctioning with no signs of mishandling by the user they can't deny FOC repair making 'out of warranty' excuse.
Consumers are at loss of money, feeling cheated, helpless & agonised and their faith is shaken by stubbornness of Samsung.
It's high time that Samsung should take an accountability of all such devices and have a plan in place before they start feeling the brunt of the users.