Shenzhou nh-50hp does not boot (CPU power supply chip is damaged)

Shenzhou nh-50hp does not boot (CPU power supply chip is damaged)

The nh-50hp of Shenzhou, the customer said that it would not be turned on after installing a sound card. The test found that it would not be powered off without installing a cpu fan, and it was detected that there was something wrong with the temperature control circuit of the cpu circuit. The ntc resistor above was normal, but the resistor below was missing, which made it impossible to divide the voltage in series. The specific maintenance process was as follows:

“Machine model” Shenzhou nh-50hp

[Fault phenomenon] No boot

[Maintenance process] I received a machine sent by my peers for repair, the model is Shenzhou nh-50hp, and the customer said that he would not turn it on after installing a sound card.

Shenzhou nh-50hp does not boot (CPU power supply chip is damaged) Figure 1

We dismantled the machine and found that the standby 3v was short-circuited. After investigation, we found that the cpu power supply chip was burned, and we bought a new chip. After installation, we found that the fault was still there. Look.blueprintKnowing that the cpu power supply chip has a program, I bought a new chip with a program again. When I installed it and turned it on, I found that there was no rsmrst＃ #. I felt that it was a bridge problem, but without a bridge, I had to get a three-board axe and brush the bios.

There happened to be a similar ec in my hand that could not be replaced, but I found that it could be turned on again. It may be that the EC was soldered, but the fan turned wildly and then lost power. After inspection, I found that the power supply of the graphics card was not out. After investigation, I found that there was less NV3V3_EN. After following the line, I found that the U6 chip did not send out the turn-on signal, but other signals were normal. After careful observation, I found that U6 had moved, and the power supply of the graphics card came out after being reinstalled, but it was still lost power after being turned on.

The test found that if the cpu fan is not installed, there will be no power failure. It is detected that there is something wrong with the temperature control circuit of the cpu circuit. The ntc resistance above is normal, but the resistor below is missing, which makes it impossible to divide the voltage in series. If you make up the startup test, you can start it normally without power failure. Because the customer has not sent a screen, you can’t test it further. Just communicate with the customer to ensure the startup.

Shenzhou nh-50hp does not boot (CPU power supply chip is damaged) Figure 2

Shenzhou nh-50hp does not turn on Figure 3

[Maintenance result] Since the peers have only communicated to ensure the startup, it can be sent back to the customer if there is no problem with the startup.