Mac Pro Power Up Issues

[bluesman714]

I have a late 2008 8 core Mac Pro that has recently begun having issues with powering up. If I leave the power cord connected for long periods of time, like I have always done, it will not power on..when I press the power button the power indicator lamp does not light, a couple of seconds later I hear a click, like a relay, then nothing. If I unplug power for a couple of hours and re-connect, it fires up normally, power indicator lights and it will run for days on end, functioning perfectly. Thinking that the problem might be hard drive related, I recently installed a solid state drive...same results.
    Power supplies are pricey for this thing. The local Apple tech can't troubleshoot at the component level. He is telling me that my machine, working properly, is only worth about $100......he could be motivated by his desire to sell me a laptop.

Yours thoughts and comments will be appreciated.

 

[mattiasNYC]

To me it sounds more like either a motherboard or PSU issue than a hard drive issue. If the power indicator light doesn't even come on I doubt it's the HD (or SSD).

I also seem to recall that earlier Mac models, at least some of them, were essentially notorious for issues with shut down/sleep/restart. So I would definitely think this is a mobo or PSU issue, most likely the former actually. I also recall having to fiddle with resetting parts of the mobo by taking out and re-seating or entirely replacing a battery on the mobo at one point to get it to work. Although this could have been on a later model.

One of the Mac Pros I work on fairly regularly still refuses to restart when told to. It'll take an eon before it shuts down, and then when the power comes back on (if it does) it'll just stay there and give the "relay clicking sound" repeatedly until I do a manual shutdown using the button, and then start it with the button again.....

They're awesome when they work, but they have far more problems than people admit and they're a b!#$ch to deal with physically because of the design.... in my opinion.

 

[pvision]

The machine runs a few checks before booting so it's logical to assume something is preventing it from starting up. The traditional advice is to remove any expansion cards, unplug all peripherals and try booting. It's definitely worth trying this first

After that it's worth zapping the PRAM / NVRAM / SMC depending on what your model of Mac Pro has. The SMC manages startup so it's a logical thing to check

The Mac tests RAM after starting - if the PSU doesn't fire up them I would assume it's not got past the initial tests and hasn't got as far as RAM tests

Best to consult someone who really knows the hardware

Nick Froome

 

[Indecline]

The same thing happens on my mac at the studio.  I've read that it's the mobo battery that needs to be replaced.. one day I'll spend that $4 to find out  ;D

 

[nashkato]

Well , today my 2006 , 2.66Ghz Xeon Quadcore has breathed it´s last breath as it seems .

on startup the powerlight´s blinking .
i took it apart completely and replaced the heatsinkpaste because the indicators suggest CPU overtemperature .

Nothing
a shame , they´re nice machines

anybody got an idea what might cause this ?

just a short search  :-[ blame on me , revealed that it should be a Ram problem , however , both Ram-Cards are fine . It seems i migh have a bad slot

 

[ubxf]

reseating the RAM , the processor cards as well as the graphic card could sometimes help. You can reset the PRAM by pressing the button on the motherboard