Laptop Model: Lenovo G485
Board Number: LA-8681P REV:1.0
Fault: No Response When Turning On, No Power
Repair Process:
Measure the common point 0V and there is no short circuit. There
is obviously no over-isolation protection.
The working conditions are measured all the way It is found that
the ACDET voltage of BQ24727 is 0V, which is obviously wrong. , and then
measured the voltage dividing resistors. PR314 and PR317 found that PR314 had
no resistance, so they were replaced decisively.
When powering
on, it is found that the capacitor is short-circuited. Quickly adjust the
voltage to 3V and touch it. If the capacitor is short-circuited, remove it.
After powering
on, the ACDET is normal at 2.8V, and the common point is also normal at 19.6V. The
memory is plugged in and the screen is connected, the boot screen shows that
the repair is complete.
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