Gigabyte ga-h110m-s2 mainboard is not powered on for repair

Gigabyte ga-h110m-s2 mainboard is not powered on for repair

Motherboard model: Gigabyte ga-h110m-s2 Rev 1.0

Fault phenomenon: main board no booting(all faults common failing)

1.no power on
2.switch without CPU VCC
3.VCC is complete and does not run away

4. Run code second auto power off

5. Run code but memory

Maintenance process:

Gigabyte ga-h110m-s2 motherboard does not power on Figure 1.

1、no power on

On the board of Gigabyte Asustek, measure that the Switch pin VCC 3.3V is normal, the standby condition is normal,short-circuit Switch,IO IT8628E_BX 104 pin has no high and low level Switch, directly dismantle FPESD1, and spike the fault.

Gigabyte ga-h110m-s2 motherboard does not power on Figure 2.

Gigabyte ga-h110m-s2 motherboard does not power on Figure 3.

Gigabyte ga-h110m-s2 motherboard does not power on Figure 4.

2.switch without CPU VCC

CPU VCC is not generated, and the conditions for generating CPU VCC are checked according to the time sequence.

1. the first point of failure is VCC1_0_PCH VCC. Measure the DFQI voltage regulator on the motherboard.

Gigabyte ga-h110m-s2 motherboard does not power on Figure 5.

Generation conditions of VC _ 0 _ PCH.

Gigabyte ga-h110m-s2 motherboard does not power on Figure 6.

2. The second high failure point of VCC without CPU is missing VCCIO or VCC is less than 0.95V V. The missing VCCIO has two failures common failing.
VCCIO is a circuit composed of an MOSFET DQ1 and a dual-channel operational amplifier 358. When 8 pin TC 107012V of DDQ1 is satisfied, the positive input terminal VCC of 5 pin needs 2.5V (this VCC also needs EN VCC, which is obtained through IO), and the output terminal of 7 pin will output one.

The abnormal performance of general operational amplifier circuit is that MOSFET does not output VCC, or the output VCC is lower/higher than normal value; Generally, this kind of fault first depends on whether the value of VCC on the positive input terminal is normal after being divided by the voltage divider resistor, and if it is abnormal, replace the resistor. The premise is that 2.5V is normal and the operational amplifier is not damaged, and MOSFET and operational amplifier should also have VCC.

Gigabyte ga-h110m-s2 motherboard does not power on Figure 7.

Quick repair method:

Gigabyte ga-h110m-s2 motherboard does not power on Figure 8.

1. when the measured VCC of VCCIO is higher than 0.5V, it can be repaired by directly replacing the resistor.

2. When measuring that the VCCIO VCC is lower than 0.5V, first measure whether the forward input terminal 2.5V is normal and the operational amplifier 12V is normal. If the operational amplifier is normal, it can be repaired directly.

3. The third high failure of VCC without CPU is the missing VCCSA VCC, and the DCQ2 is damaged and replaced directly.

Gigabyte ga-h110m-s2 motherboard does not power on Figure 9.

Gigabyte ga-h110m-s2 motherboard does not power on Figure 10.

3,VCC all, no code running

When the memory VCC, bridge VCC and VCCSA VCCIO are all normal, there is still no CPU VCC, and the VDD VCC of ISL95858 is insufficient, which is 5V normally. There are two reasons:

Gigabyte ga-h110m-s2 motherboard does not power on Figure 11.

There are no DAR7 and DAR8 resistors installed on the motherboard. The 24 pin VDD of ISL9585 is directly VCC by DAQ5MOS tube, while the VDDP of 32 pin is directly VCC by 12V through a DAR9.

Gigabyte ga-h110m-s2 motherboard does not power on Figure 12.

Repair idea 1:

When the 12V and 5V of DAQ5 are normal, replace DAQ5 directly.

When DADR1288,12V passes through the resistor,VCC is not 12V, replace this resistor.

Gigabyte ga-h110m-s2 motherboard does not power on Figure 13.

Repair idea 2:

If the measured VDD of ISL95858 is only 4.0V-4.35V, but less than 5V, the DS pole VCC of MOSFET is equal, which means MOSFET is completely turned on, so trace the source of 5V forward.

Gigabyte ga-h110m-s2 motherboard does not power on Figure 14.

The lack of 5V in 5VDUAL is caused by R57 resistor, which causes 12V to fail completely, and it can be repaired by a lump of tin or another resistor.

Gigabyte ga-h110m-s2 motherboard does not power on Figure 15.

Gigabyte ga-h110m-s2 motherboard does not power on Figure 16.

1. Run code seconds auto power off

This VCC is normal at 2V, so it can be disassembled directly, and a lump of tin of 125 and 124 pin can be fixed.

Gigabyte ga-h110m-s2 motherboard does not power on Figure 17.

5, run code but memory

There are two cases of memory failure, one is that the Capacitor of the memory VCC is poorly filtered, and the other is that it can be solved by repeatedly running the code without memory, and brushing BIOS.