Gigabyte B150M is powered on and powered off 

Gigabyte B150M is powered on and powered off

“Machine model” Gigabyte B150M

【 Fault Phenomenon 】 Power on and power off

[Maintenance process] I received a desktop motherboard sent by a customer for repair, the model of which is Gigabyte B150M. The fault is that I switched on the power and pressed the power-on key to turn on and turn off the power.

Measuring the power supply of the motherboard found that most of the power supply was available, but SLP-S3 was always turned off by IO, which led to the power failure of the whole machine. When measuring from the back to the front, it was found that the CPU power supply did not come out. This motherboard was powered by a three-phase CPU. When we measured the conditions of the CPU power supply tube, we found that the 12V voltage from one motherboard was pulled down to 0.6 after passing through a resistor. V, this is definitely not right. After removing the tube, the voltage returns to normal, which means that the voltage is pulled down due to the damage of MOS tube. After replacing it with a new power supply chip, it is found that although 12V will not be pulled down, the CPU power supply is still not available. Measure the opening, power supply, SVID signal waveform and voltage of CPU power supply.

Gigabyte B150M power-on and power-off Figure 1

Then we directly replace the CPU power supply chip, and after the chip is powered on, we find that the CPU power supply has come out, but only two ways.

Gigabyte B150M power-on and power-off Figure 2

This may be a problem with the circuit design. We connected the motherboard to the screen and started the test, and found that it can be started normally at this time.

Gigabyte B150M power-on and power-off Figure 3

[Maintenance result] There is no problem in the peripheral interface and card slot of the test motherboard, and the baking machine is normal, so the maintenance is over.