Lenovo G31T-LM Motherboard power supply Abnormal maintenance

A Lenovo G31T-LM motherboard, CPU core voltage, reset, PG, North Bridge all power supply is not normal, memory voltage 1.4V significantly lower, and later found that North Bridge power supply is the memory of MOS tube power supply, measuring memory power supply MOS tube is not a problem, MOS tube g pole attached to an IC APW7120, This chip is easy to break, and later in the scrap board to dismantle a loaded up, still not, check a half day headache, and then found 24P socket next to a 8 feet 2539 of the field effect tube measurement is no problem, but the output voltage is not normal, change, the motherboard to measure all the power supply all normal, boot into the operating system, Let the computer test run 3-hour failure no longer, this motherboard repair success!