Address
304 North Cardinal
St. Dorchester Center, MA 02124
Work Hours
Monday to Friday: 7AM - 7PM
Weekend: 10AM - 5PM
Maintenance of wx b450 mainboard after startup and power failure.
A b450 motherboard is turned on and powered off, which can be triggered again.
There is no short circuit in the board measurement, but there is no standby 1.8v power supply, and the power supply of the measurement chip is normal. If you change the chip directly, the measurement is actually 4.9v Fortunately, it is not directly connected to U, otherwise U will hang up.
Measuring the voltage of each pin of the chip, it is found that fb pin is 3.6v Is the chip bad? This foot is inblueprintI didn’t see the connection anywhere else, so I changed another chip. This time, there was no voltage of 1.8, and fb was still 3.6. I tossed around here for a long time. I had to tear the cloth, but the chip was changed for three, but it still didn’t work. Finally, I accidentally clicked on the back and saw that it actually reached the back.
Back to the bottom here, replace the chip 1.8, trigger or second power failure, this is a big head, standby voltage is normal, trigger or second power failure.
There’s no way out, power it on forcibly, short-circuit the power supply to power it on forcibly, measure that there is no cpu power supply, measure that there is no voltage when the chip is turned on, and remove the 6-pin chip below or there is no voltage.
Then remove the following one and open it. Is it actually a short circuit when measuring slp s3?
It’s amazing that the slp s3 roast chicken didn’t come out at once, but it didn’t short circuit after cooking.
But, but it still triggers the second power failure, but the forced power-on measurement shows that all voltages are normal, and the clock is reset, and then it suddenly occurred to me that since the voltages are normal, can the machine be turned on?
So I installed the U boot, and the magic thing appeared, that is, I short-circuited the power supply first, and then triggered the boot pin, which actually turned on the machine normally and turned it off normally.
