Mac Pro PSU fan not spinning...
System: Mac Pro (early 2009)
After a while the system shuts itself down, and then repeatedly does so while trying to boot back up. After letting it sit a couple of hours, it boots back up, but again starts shutting itself down.
I opened it up and noticed the PSU fan was not spinning - which eventually caused the PSU to overheat and power off.
I ran a hardware test, and got the following error...
4MOT/1/40000002: PS-0
I searched on the Internet for this error, and it seems (I assume) that this error means the PSU fan is bad, but I plugged it into another fan port on the motherboard and it worked fine. I then, plugged one of the other fans into the PSU Fan port and it did not work.
I reset the SMC.
I reinstalled the OS (Snow Leopard)
I loaded "Fan Control" software (PSU Fan stays at 0 RPM and cannot be manually adjusted.)
At this point I'm guessing it's either the power supply itself (which I find hard to believe), or the PWM controller for the PSU Fan is not working. To get around the issue, I'm ordering a "simple" (2 wire for power only) fan to replace the built-in fan and a manual (knob) speed controller. (Total of $10, until the real issue can be determined.)
If anyone could help any further, I'd appreciate it.
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Wanted to add reason I didn't think it is the PSU...
Red LED flashes when power cord is plugged in and again when it's unplugged.
PSU PWROK LED is green
5V STBY LED is amber
Tags: Mac Pro, 2009, PSU, power supply, fan, PWM
Mac Pro, Mac OS X (10.6.8)