Since Nokia C2-03 is a slider phone and used a UI flex (flexible ribbon cable), that is use to connect the LCD screen display from the main PCB board. Now in fixing backlight problem on the display, we must always consider that the flex is vulnerable and may cause the problem.
Here how to troubleshoot the Nokia C2-03 backlight LED problem:
For quick fix, on minor problem like if the phone status shows no indication of being wet by any liquid, free of oxidation build up or the PCB board is still clean.
- Check the Flex ribbon cable wire.. replace if damaged.
- Check/ try to replace the LCD screen, the white LEDs on it may already been busted.
This figure shows the connection line paths of the backlight LEDs on Nokia C2-03 UI flex cable. There are two white LEDs also mounted on both sides of the top part of the flex. This two LEDs were also connected to the inner backlight LEDs of the LCD screen.
Take note: the LCDs backlight is also connected in parallel circuit like the two LEDs on the flex - meaning if that two LEDs was still able to light up but not on the LCD, it means that the LCDs backlight LED is already busted. So check that out...
View in larger image.
The Nokia C2-03 backlight driver components.
In this figure shows the detailed components or parts that is called "LED driver circuit".
This will cause the display backlight loss if one of these components being damaged and or each of its connection line paths breakdowns. This circuit may only damaged if the device suffered wet or water damaged that resulted into oxidation build ups and then caused a short or open circuit.
view the larger image .
So, check out these parts:
- Clean these components surface if necessary.
- Check each of the filter coils first. Replace if found damaged.
- Trace the VLED and VBAT_BB connection line paths - point to point to the corresponding capacitors, filter coils and including down to the Flex pin connector.
