one No power maintenance 1, South bridge power supply 2. I/0 Power supply 3. Gate circuit (VCC)4. XY(voltage at both ends) 5. coms Battery 6. Jump(jumper cap) 2. 5V-----3.3V7, Power-on transistor 5V8, 5VSB9, power-on
1, check the power supply of the clock chip 3.3-2.5V, measure the surrounding inductance or resistance greater than 0 ohms. 2. Measure whether the crystal oscillator of 14.318 works normally, and measure two feet in turn, and the voltage is 1.5-1.6V. 3, Power-ok is there 5V voltage, if not, follow the line to check the circuit.) 4. Measure whether the clock signal of the south bridge is normal, and the voltage of 330,220,110 next to it is 1.6V. 5, the south bridge power supply should be normal, the quantity MOS,1117 has no 3.3 or 5V power supply (6, the quantity 32.768 crystal oscillator is normal intel 0.5V VIA 1.5V7, the voltage on the reset switch is 3.3V or 5V, if there is no voltage, check the line along the switch, generally leads to two gate circuits, Or one foot leads to the gate circuit and the other foot leads to the gate circuit. 8, detect the gate voltage 3.3V-5V. 9, the amount of PCI, AGB, IDE, I/O reset foot to the ground there is no short circuit. 10. Check whether Vcore is normal. 11, measure ATX power supply 3.3V, 12V, 5V is normal.
FF maintenance, 1, under the normal voltage of each group, the earth resistance value of each bus 2, the CPU to the north bridge 32 address lines, 64 data lines to the ground resistance value of 350-750. 3. Earth resistance value from South Bridge to North Bridge 350-750. 4. The ground resistance of the AD line from the south bridge to PCI should be the same. 5, Measure BIOS clock, reset, AD line. 6. Brush BIOS. 7, clock IC power supply. 8, memory power supply