MP 1,1-5,1 Mac Pro 4.1 2009 - won't start , power button stuck

[JoeStrummer]

Hello!
I'm trying to revive a Mac Pro 2009 4.1 that's been on my shelf for a couple years
When I attach AC power cord, immediately the green light above the power button on the front panel comes on, and stays on, solid, but the power button itself is not responsive, the machine won't turn on or off. None of the fans run.

When I attach the AC power cord, the top two diagnostic led's on the logic board flash red once

If I push the 'DIAG_LED' button the '5V STBY' goes orange but that's it.

Otherwise no response from anything

Any advice or suggestions grat3efully received

Thansk
Neil

 

[tsialex]

These are the DIAG LEDs that need to illuminated when you press the DIAG button (see page 30 of the early-2009 Apple Technician Guide):

1. PSU PWROK (green),
2. 5V STBY (amber),
3. EFI DONE (green),
4. GPU OK (green).

Clean and inspect each connection, apply appropriated contact cleaner to the memory slots and DIMMs, PCIe slots, PCIe cards and to CPU tray/backplane connector.

Did you check the BR2032 RTC battery voltage? MacPro can't boot if the battery is spent, replace it with another BR2032 - do not use a CR2032 except for tests.

You can always start the Mac Pro jumpering SYS_PWR solder pads on the backplane board (see page 38 of the early-2009 Apple Technician Guide).

There are dozens of threads here about this topic, use the search.

 

[JoeStrummer]

Thanks tsialex!

Your feedback and knowledge is always appreciated. I have done a search through previous threads but can't seem to find one with my particular problem...

When I insert the AC power cord, the green light above the 'on/off' switch on the front panel comes on. But the 'on/off' switch (power-on button) is not responding. I can push it or hold it down for 20 secs , no response , no chimes , no fans running, machine is just dead. If I unplug the AC power cord, the light on the front face panel goes off. Plug the AC power cord in, light goes on

My best guess is a faulty 'power button', but before I tear the whole machine down I was wondering if anyone had any other suggests?

Thanks!

 

[tsialex]

My best guess is a faulty 'power button', but before I tear the whole machine down I was wondering if anyone had any other suggests?

Check the RTC battery voltage, jumper PWR_SYS, then replace the PSU.