Mac Pro 3,1 not booting!

A couple of weeks ago i turned on my mac pro and it didn't boot!
The video card fan whirls around for about 5 seconds and clicks off.
After looking around this forum and others for a while i thought it might be a power supply issue. So i took the tower to my local Apple repairer to get fixed. I called a week later to find out what the deal was and was told that its not the power supply and they were still looking at it. A few days later i got a message saying that it had bad ram and was fixed. leaving me 2gig of ram down (i had 8 gig of ram leaving me with 6 gig) and $75 out of pocket.
No sweat!
About a week later it did it again! Not booting!
i push the power button a few times and it booted! Phew!
It did this for a couple more weeks. Not booting sometimes. A few pushes of the power button and away we go.
Until of course i had a recording session booked and the mac pro would not turn on at all!
I've taken all the ram out (8 1gig sticks) and just installed 2 gig at a time. Going through all of them. Even the one the repairers said was bad. With no luck. I've reset the SMC and take the battery out and put a multi meter over it and it seems fine. (I must say that one day the screen went all weird. Kind of like blurred checkers for a minute but came good again.) I tried to boot it up without the graphics card, no luck!
I'm not sure what i should do??
Take it back to the repairer for another $75 or buy some more ram and see what happens.
Is it possible that ALL the ram is stuffed?

Any advice you guys could give me would be greatly appreciated.

Thanks heaps
Damien

Ah hah! It all started after a really hot day! So they won't boot without a video card??

can you boot up a mac pro WITHOUT a video card???

I'm really starting to think its the video card...
I had the battery and the video card out this arvo and just the power cable in and notice that the ram card LEDs were staying on red. And a LED up near the Airport card glowed as well.
I pulled the power out. Installed the back the battery and card and turned it on and it still doing the same thing. Fan running for about 5 seconds and thats it.

Can anyone tell me if you can boot up a mac pro without a video card??

Cheers

Thanks heaps for your replies!!

The invoice sadly states that no refunds on service work that is not covered under warranty....

i Just had another look with the battery in but no video card. And the LEDs are turning on, then turning off. Just like what happens WITH the video card in.

I'm starting to think it might have to go back to the repairer...

Thanks MacTruck!

I was told the first time i took the MP to the repairer that it wasn't the power supply...

I'm just hoping it's not a logic board....$$$$$$

Cheers!

----------

I've taken the MAC PRO back to the repairer.
I'll post when i get it back.
Fingers crossed its not a expensive repair....

logic board fail

Its the logic board. $906 to replace.
Not sure what to do now.
The MacPro was for my recording studio. I use a digidesign 002 firewire audio interface and a 42inch LCD display.
Should i go i7 mac mini for around $1000 or get it fixed???
i've got a 13inch macbook pro but it locks up running pro tools on the 002 and the monitor through thunderbolt to vga.
So i guess my question is what would be better? Fix the 8 core mac pro or get a mac mini?? (i don't have the cash to get a new mac pro


(I'm leaning towards fixing the MP. It did what i needed it to do..)

logic board fail

Thanks for the reply!

How easy would this be to replace myself? I'm good with a soldering iron!
Or is this a tech job?

Cheers

logic board fail

Thanks 666sheep! \m/

Is there any way i can test if the logic board is the problem? The report i got back from the mac repairer is:

replaced PSU-failed. Machine still powering off.
*removed all parts from the machine except for MLB, CPU and PSU - FAILED. Machine still powers off.
Looking like MB

Could it not also be the CPU?

Also the SERVICE MANUAL seems to be hard to find. Am i looking for a hard copy or a download? I found a website that claim to have the download manual... For a fee.....
I'm thinking i could just film every lead/screw ect i unplug step by step so i can play it back when i'm putting the new MB in.

What do you think? To risky? Keep looking for a service manual?

The northbridge heat sinks aren't expensive so i'll throw a couple those in if you think its worth it.

Again thanks heaps for your advice!

HORNS UP \m/
omen

logic board fail

Yep that little LED up near the airport card is glowing when attempting to boot the machine.

Its really looking like the the logic board.
The repairer ordered a new power supply and swapped my one for a new one and the machine failed.
So i can rule the PSU out.
It won't boot with the video card or the ram boards out so i don't think its that.
The repairer basically took every out and tried to boot. But nothing.

I read the service manual (thanks 666sheep) and push the Logic Board Diagnostic LEDs buttons and nothing bad comes up.
I've got:
trickle power.
GPU good
EFI done

Doesn't say the CPU's are bad or errors.

i really think its the mother board....

I tell ya its a bit daunting to throw down a few hundred bucks on a motherboard on a self diagnosis!!!
But i'm thinking i can do it!

I'll keep looking into it over next few days before i buy a new board and if anyone wants to put their 2 bob in i'd greatly appreciate it!

Cheers

omen