Mac Pro Tower A1289 Boots to the Apple Loading screen then turns off

[ClanStrachan]

Mac Pro Tower A1289
It boots to the Apple Loading screen then turns off
Sometimes it goes a tiny bit, sometimes half way, but always turns off.
When I remove the hard drive bay, it boots to the question mark and doesn't turn off.
Booted hard drive externally and it booted once but never again.
Reset PRam, NVRam, and SMC
Removed all Ram sticks and tried different ones to see if that was the issue. Same issue.
Can boot into Single Sign On mode and did repair the disk once.
Can boot into the disk selection mode but still turns off when I choose the main drive or the recovery partition.
Will not boot into recovery mode
Tried a SSD and a regular HDD.
Will not go to hardware test connected to ether or not with option d or just d
Pics of lights included. Lights that light up on the backplane logic board are PSU PWR ON, 5V Standby, Sys PG, EFI Done, and GPU ok.
Can't decide if it's corrupt OS (No recovery or install disk to try to reinstall OS), GPU, PSU, or Backplane logicboard.
Any help is appreciated, thank you in advance!
https://imgur.com/a/2Z6RFmM

 

[pigoo3]

When I remove the hard drive bay, it boots to the question mark and doesn't turn off.
Booted hard drive externally and it booted once but never again.

I'd say try a new or known working hard drive.

- Nick

 

[ClanStrachan]

I'd say try a new or known working hard drive.

- Nick

I did. It's not the drive or the OS. Put the drive in another mac, booted perfectly.

 

[pigoo3]

Booted hard drive externally and it booted once but never again.

I guess this statement had me confused. When you said it "booted once"...sounded like when you tried additional times...it didn't.

But then it also wasn't clear if you were using the Mac Pro's internal HD on the Mac Pro externally...or a different computer.

- Nick

 

[pigoo3]

Can you tell us if you've owned this Mac Pro for a while (and it worked fine previously)...or if you recently purchased it & it was purchased not working?

Thanks,

- Nick

 

[ClanStrachan]

Worked fine for almost a year.

Sorry. I tried the SSD and HDD in the bays and externally multiple times. Out of probably 50 boots, it only booted to the login screen twice.

Connected both drives to another mac and boom, booted up right away no issues, multiple times. Indicating no drive or OS issue.

Weird part is, according to the service manual, the light configurations it's giving, says that the PSU and Backplane Motherboard are good. SO CONFUSED.

 

[pigoo3]

A big issue is that the computer won't boot externally or internally. Generally on many desktop computers there's a data cable between the HD and the logic board. I think with these Mac Pro's the HD plugs right into a socket on the logic board...and externally the external ports are also located on the logic board. Thus internally or externally there are no cables to be bad.

Plus you've already tried all the resets.

He's a crazy long-shot idea. Have you tried booting the computer into the Recovery Partition of this HD?

- Nick

 

[ClanStrachan]

Yeah so it will not go into recovery mode. And you’re correct, no cables, all on the logic boards themselves directly.

I tried to boot the drives in another Mac and they booted perfectly. So not the OS or drives.

 

[chscag]

Two things on that machine you might check: The power supply and your graphics card. If you have another graphics to swap, give that a try. Older Mac Pros are also susectible to failing or weak power supplies which can also cause the symptoms you discribe.

 

[pigoo3]

Agree with chscag. Could very well be a weak power supply.

- Nick

 

[ClanStrachan]

Two things on that machine you might check: The power supply and your graphics card. If you have another graphics to swap, give that a try. Older Mac Pros are also susectible to failing or weak power supplies which can also cause the symptoms you discribe.

So I actually removed the GPU to see and it still did the same thing. So i guess it's the PSU?

Can I get a PSU for this machine like at a Fry's Electronics?

 

[pigoo3]

Can I get a PSU for this machine like at a Fry's Electronics?

Not sure...I kind of doubt it. The PSU for a Mac Pro is kind of flat & long shaped (like the shape of a stick of gum). Not the normal square or rectangular box PSU you see for Windows computers.

eBay probably your best choice for a replacement. Get ready for some "sticker-shock"...they ain't cheap. Especially a new PSU (can find used one's too).

HTH,

- Nick

 

[gsahli]

I've had luck with a used power supply from dvwarehouse.com