GigabyteGA b75m-d3v computer power down repair

Jijia b75m-d3v computer auto power off, remove Q16, power on normal run code, this board repair.

Gigabyte b75m-d3v computer power down repair.

Machine model: Gigabyte b75m-d3v Rev: 2.0.

Fault phenomenon: computer auto power off.

Repair process: the workbench can test auto power off, but it can continue switch. Moreover,auto power off is very fast (half a second). It feels slower than CPU Short circuit and a little faster than IO detecting auto power off.

Gigabyte b75m-d3v computer power down maintenance

Gigabyte b75m-d3v computer power down maintenance diagram 1.

See this situation, of course, first look at Io vin123 detection 2.052.01 1.98 normal, do not close IO detection problems.Therefore, if the power is forced on, the IO detection can be tested at most. The large VCC can not be detected. Each VCC test shows that the VCC value only floats to half and then drops down, or even fails to reach half.

Gigabyte b75m-d3v computer power down maintenance

Gigabyte b75m-d3v computer power down maintenance diagram 2.

The pwrok1 GND can only be lowered according to the old method.However, the signal of this board does not have Capacitor of GND, so me is adopted_Pwrok to remove the battery holder, C206 Capacitor remove short-circuit.

Gigabyte b75m-d3v computer power down maintenance

Gigabyte b75m-d3v computer power down maintenance diagram 3.

Generally pull down apwok, in addition to CPU VCC does not come out, other large VCC will come out and not Restart repeatedly.But this will also be Restart repeatedly auto power off.However, the speed of auto power off is much slower than before. It takes more than a second to power on. At least multimeter has enough time to test.
Test: memory 1.5V is normal
PCH 1.12v normal
PLL 1.86v normal
VTT 0V abnormal
Vccsa 0V abnormal

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Gigabyte b75m-d3v computer power down maintenance diagram 4.

VCC is missing.When Restart repeatedly is measured, Q20 C level has stable 0.7V, and B level can float to more than 0.6V when power on, then Q20 may be broken.

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Gigabyte b75m-d3v computer power down maintenance diagram 5.

The new one is still auto power off, so remove Q16. Do not control and keep VTT_EN long-term, have removed Q16 normal run code, this board repair!

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Gigabyte b75m-d3v computer power down maintenance diagram 6.

Summary: the VTT fault of 1155 pin plaorm is auto power off. Generally, the speed of auto power off is relatively fast, and the same is true for other brand boards.