MP All Models Mac Pro 2009 not powering on

I hope not but seems logical. Is there any noise at all ? clicking etc ?

I had a very odd problem with my 2010 Mac Pro 5,1. It would occasionally not power on, sometimes after I got it to power on I could not power it off from the front power switch. Sometimes only after multiple presses on the power switch it would turn on. Of course it would power off after pulling the power cord. Of course this problem occurred randomly. After re-examining my software and OS I concluded that there was no software issue. I got a quote from a local computer service center to service the machine for $800. I decided that before I would junk the machine or replace the power supply I would do some basic trouble shooting, examine the hardware and use the little experience I had in assembling personal computer systems. I suspected an issue with the power system. I started trouble shooting guided by Apple's Technician Guide which can be found on the internet. The power supply tested out okay.

The long and short of the story is that I took out all major components and inspected connectors and reseated them and re-tested sequentially. The problem turned out to be the front panel power switch connector. When I first looked at the front power switch connector there was a tiny bit of gold shining in a nearly impossible to see gap between the male power switch connector and the connector on the small PC board it plugs into on the front of the machine. I wasn't even certain I could see the gap with my bare eyes. I took out my phone and using the camera's magnifying feature, confirmed that there was a tiny gap. I thought to myself that this could not possibly be the issue but went ahead and disconnected and re-seated the front power switch connector. I immediately tested the computer system.

The machine is still working properly to this day.

scouser75 said:

Thanks guys. I'm going to look up how to disassemble the power socket and also look inside the tower this weekend.

Dataid, your instructions are great and hopefully my situation will be the same as yours. Fingers crossed!

Click to expand...

i hope you have an easy fix for your problem, but if its not what was stated, then you have to check each hardware individually. this happened to me where the mac power button would light up then turn off. i had to buy another mac pro basic configuration off ebay for 100 dollars then swap out the power supply and cpu tray to test them. at the end i concluded that it was the mother board, i bought another motherboard and it worked.

OP, have you done the diagnostic LED light test? There are diagnostic LED lights on the backplane that can tell you many things...

Look inside, to the left of the fan: