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 led light on main power 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 button 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 )
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 are 0v, and on pin 2 it is 2,8v, pin 3 it is 3,7 v
So far i tried check for short (didnt find),replaced mosfet but the same; then i removed 0 ohm resistor R5620 and now i have a light on main power button...but problem is still present on the other side signal PWR_LED_CON# which is generated from touchpad button ? according to the scheme...but i dont understand how?
I measure every pin from touchpad button on working and this laptop and only difference is in pin 9 PWR_LED_CON# ...on working laptop is 0 v but on this it is 2,7 V. I am not able to figure how PWR_LED_R# is generated?
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