Sunburn (Faded) on LCD Screen (Noxxa Breadmaker Oven BM315SC)
"Sunburn" on an LCD screen, also known as screen burn-in, refers to permanent discoloration or ghosting of areas of the screen due to prolonged display of static images. This occurs because the pixels degrade over time, especially when exposed to high brightness and static content.
An LCD polarizer is a filter that controls light waves. It’s designed to block light waves of a certain polarization while simultaneously allowing light waves of a different polarization.
In LCDs, polarizers are used to produce visible images. A polarizer is a layer of light-filtering crystalline material. There are typically two polarizers in LCDs, both of which control the type of light that passes through them.
LCDs contain a lighting system, known as a backlight, that illuminates their pixels. Before reaching the pixels, though, light must pass through the polarizers. The polarizers are responsible for creating visible images by controlling the brightness of the LCD’s pixels.
The LCD screen will begin to degrade at very high temperatures. Overheating the display can cause dark spots to appear or result in a fully dark screen. Both internal and external heat should be taken into consideration when operating the display.
Similarly, this applies to LCD Screen on calculator, watch, multimeter, aircond remote controller, etc.
Possible Solutions:
- To change a new reflective polarizing film at the back layer of LCD Screen (no specific film is recommended, might need to try and error)
- with/without silver reflective layer?
- with/without backlight (WB) version?
- with 45-degree / 90-degree polarization?
- which correct film size to buy?
- might need to apply screen removal liquid?
- To replace the whole LCD Screen with a new LCD Screen
- After comparing the price differences and complexity, it is better for me to change the whole LCD Screen module to a new unit directly.
- By changing the reflective polarizing film, it might not guarantee the outcome as this is my 1st time handling this sunburn LCD Screen issue.
- Changing a new LCD Screen module will be much easier by just doing a bit of soldering, with 100% guaranteed outcome.
- Dismantle the metal housing, refer to DIY Series 60: Repair Noxxa Breadmaker Oven and install the new upper heating elements (another fixing which is not related to LCD Screen)
- Unscrew 7 screws in order to remove the main PCB from the front panel (you will need flexible screwdriver in this case)
- Top view of the main PCB
- Bottom view of the main PCB
- Lift / Bend the LCD Screen (already removed the reflective polarizing film) slightly to remove the LCD Screen holder
- Cut the pins on LCD Screen, desolder all pins and remove it from the main PCB
- Put back the LCD Screen holder, then place the new LCD Screen align to the via hole on PCB
- Some soldering works to fix the new LCD Screen on board
- Assemble the PCB and metal housing, then test the new LCD Screen
- Testing the new LCD Screen
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