[SOLVED] Mac Pro having issue with booting

[Ruben_20]

Hello yall.
My Mac Pro (Early 2008, running on 10.8.5) have issues with booting. The machine starts, and after only a couple seconds, it just shuts down. Then, when I start it again, it gets a bit further into the booting process, and after 4-5-6 attempts, getting closer every time, it finally goes all the way and boots properly. This happen almost every time I boot.

I used to have a different kind of booting issue a short while back, when it sometimes started the booting process, with fans and all that, and after a couple seconds, it shut down. All I could do was to wait a while, and then the problem was gone for a few weeks or months. I brought it to a service place, and they had to wait a week to get started on the machine, and then the problem was gone(ofc). So I did a clean install of OS X, but that doesn't seem to have made any difference.

Any thoughts on this?

 

[Ruben_20]

I tried putting my harddrives in a different mac pro, and it works like a charm, so it's obviously some sort of hardware problem. But which part is responsible?

 

[McHenryB]

Apple Hardware Test ( https://support.apple.com/en-gb/HT201257 ) might help to pinpoint the problem. But, let's face it, it's almost certainly going to be something on the main logic board so the whole thing will need replacing.