12-03-18, 12:26 PM
Puedes ver la teoria de la version China, en ella el responsable es U1602, el ic se encuentra abajo del porta sim blindado.
las can be seen from the figure above: U1602 hace a built-in backlight circuit, L1604 is a boost inductor, and D1603 is a rectifier diode.
The positive power supply LED_A of the backlight output from U1602, is sent to the display interface J1701 via the LB1603. The loop signal output from the U1602 LED_K1 LED_K2 is directly sent to the display interface J1701.
If there is no light failure, first check the coupling inductance LB1603, check and measure L1604 (in good condition, use a multimeter to measure both ends of the inductor and value is short-circuited. If there is any resistance or infinite resistance, it means that it is broken. Must be replaced).
After replacing LB603 and L1604, replace U1602 and replace rectifier diode D1603.
las can be seen from the figure above: U1602 hace a built-in backlight circuit, L1604 is a boost inductor, and D1603 is a rectifier diode.
The positive power supply LED_A of the backlight output from U1602, is sent to the display interface J1701 via the LB1603. The loop signal output from the U1602 LED_K1 LED_K2 is directly sent to the display interface J1701.
If there is no light failure, first check the coupling inductance LB1603, check and measure L1604 (in good condition, use a multimeter to measure both ends of the inductor and value is short-circuited. If there is any resistance or infinite resistance, it means that it is broken. Must be replaced).
After replacing LB603 and L1604, replace U1602 and replace rectifier diode D1603.
