Rep: 23
2
1
Hi
as in photo below
if the line
BUTTON_TO_AP_HOLD_KEY_L
from power ic to GPU
was cut by removing resistor etc
what are the effects
and what are the function of
BUTTON_TO_AP_HOLD_KEY_L
Is this a good question?
Rep: 221.5k
15
290
807
That resistor is a "pull-up" resistor. Designers use pull-up (or pull-down) resistors so that the state of the signal, in this case BUTTON_TO_AP_HOLD_KEY_L, is in a known state; in this case @ 1.8V (or "high" or "1") unless the line is brought down to 0V.
The line designator explains what it does...button (hold key) to application processor with an active "Low" signal. Basically, if the Power button is pressed, it's signal will go Low and it will notify both the PMIC and the CPU of this for appropriate downstream actions. Just follow it through the schematic to see where it goes.
EDIT 2017/10/6
Think of the circuit like this:
Now imagine that you cut a line or remove components and you will have a better understanding of what the impact is.
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if we cut the line
what are effects
and basically what is the utility of such line
thank u very much
this line is come from power ic and divided into 2 line
one for power switch key
another on for gpu
so if the one to power switch key is ok
but we removed or cut the other one going to gpu
what will happen
see my edit to the answer...
thank u man u really helped me
Rep: 23
2
1
hi
Eng ahmed tahseen team from Egypt did it
they removed the resistor
and the result
continuous rebooting
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