So, this laptop was broken..i tested it..find short...replaced ite chip and 3/5 voltage regulator and everything is working fine...i tested it and all ok...but...later when i tried to put it together every time i connected touchpad button the red light on the power button was missing (the laptop is working, touchpad is working) just missing that red power button light). And when i unplug touchpad it was there... So whats going on...?
I measure power led on both side and it is 5,06 V on one side...but when touchpad is connected there is a difference on other side "PWR_LED_CON#_1" ...when touchpad is not connected it is 3,26 V but when connected it is 3,7 V. Ok, so that it is why i dont see red power button light...
So i inspected touchpad ribbon cable and connector and everything seems fine...i even used a second touchpad button of the same model i have and same...no red light when connected. Oh and i should mention that touchpad button is working fine when connected...only no power light on main button.
So i use schematic (attached similar model but should be the same) and i found following:
1. PWR_LED_CON#_1 without touchpad 3,2, with touchpad 3,7
2. PWR_LED_CON# is on pin 9 of touchpad...should be 0 v but it is 2,8 V. Also it is shorted with 0 ohm resistor to a "PWR_LED_R#" (gate on mosfet see attached picture below)
3. Without touchpad connected the readings on n mosfet are pin 2,3 0 v, pin 1,4 GND, pin 5,6 are 3,3 V (i believe this is ok, as it shoud be always)
4. When touchpad connected readings are on pin 5,6 0v, and on pin 2 2,8v, pin 3 3,7 v
So far i tried check for short (didnt find),replaced mosfet but the same....
I measure power led on both side and it is 5,06 V on one side...but when touchpad is connected there is a difference on other side "PWR_LED_CON#_1" ...when touchpad is not connected it is 3,26 V but when connected it is 3,7 V. Ok, so that it is why i dont see red power button light...
So i inspected touchpad ribbon cable and connector and everything seems fine...i even used a second touchpad button of the same model i have and same...no red light when connected. Oh and i should mention that touchpad button is working fine when connected...only no power light on main button.
So i use schematic (attached similar model but should be the same) and i found following:
1. PWR_LED_CON#_1 without touchpad 3,2, with touchpad 3,7
2. PWR_LED_CON# is on pin 9 of touchpad...should be 0 v but it is 2,8 V. Also it is shorted with 0 ohm resistor to a "PWR_LED_R#" (gate on mosfet see attached picture below)
3. Without touchpad connected the readings on n mosfet are pin 2,3 0 v, pin 1,4 GND, pin 5,6 are 3,3 V (i believe this is ok, as it shoud be always)
4. When touchpad connected readings are on pin 5,6 0v, and on pin 2 2,8v, pin 3 3,7 v
So far i tried check for short (didnt find),replaced mosfet but the same....

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