Mac Pro working but logic board LEDs on when computer off!

Hello. I obtained a used mac pro 5,1 and it appears to work perfectly (even passes Apple Hardware Test without problem) — but when I first plug the unit in (supply power) without starting it up — — the S3 LED is green and the “PLT RST” LED is RED continuously (see picture).


AFTER STARTING THE UNIT… the following LED’s burn continuously GREEN:

3.3V, 1.5V, 1.05V in upper bank

S0 in middle bank

X1 PG, and 5V in lower bank


AFTER “Shut-Down” from Apple Menu, the S3 LED is green, and the “PLT RST” -and- “RSM RST” burn RED continuously.


Please Help! I was told that this machine was used as a server. I turned off all the “Wake On LAN” stuff I could find… but the lights still burn! I’ve searched the web and tried the macrumors website without success. I even tried to glean information from the intel website without solution. THANKS IN ADVANCE!


http://forums.macrumors.com/showthread.php?p=20502657

http://www.intel.com/content/dam/www/public/us/en/documents/datasheets/5-chipset -3400-chipset-datasheet.pdf


User uploaded file

Posted on Jan 3, 2015 9:38 AM

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Posted on Jun 13, 2015 1:30 PM

I'm tagging this thread to announce my discovery related to this device.


I've recently determined that this device is INDEED an authentic Apple SERVER PROTOTYPE -- and that the observed behavior of the back-board status LEDs (expressed in my previous posts) precisely matches the specifications documented here: http://tim.id.au/laptops/apple/xserve/xserve_early2009.pdfUser uploaded file

Thank you for your [lack of] feedback -- it helped me realize that this device was truly unique! :-)

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Jun 13, 2015 1:30 PM in response to ~jj

I'm tagging this thread to announce my discovery related to this device.


I've recently determined that this device is INDEED an authentic Apple SERVER PROTOTYPE -- and that the observed behavior of the back-board status LEDs (expressed in my previous posts) precisely matches the specifications documented here: http://tim.id.au/laptops/apple/xserve/xserve_early2009.pdfUser uploaded file

Thank you for your [lack of] feedback -- it helped me realize that this device was truly unique! :-)

Jan 25, 2015 4:12 PM in response to ~jj

Okay; here's what I've learned.


I spent a good deal of time analyzing the "misbehaving" Mac Pro 5,1 and another "behaving" Mac Pro 5,1 (4-core instead of 12-core). ALL the buss voltages and internal temperatures were highly correlated; also, all the hardware reported similar model numbers and performance. Additionally, the "misbehaving" unit (the ones with the LED's burning when powered off and on) seemed to perform flawlessly: I was able to create BootCamp partitions and even run Windows diagnostics and utilities against the unit. I finally decided to seek direct Apple Support.


Apple support was very generous in communicating with me (I had another problem with the unit that afforded me free access to senior Apple technical personnel); after a careful review by a senior support technician, he stated that continuously burning status LED's were indeed symptoms of probable problems -- but only a "thorough hardware diagnostic" (available only at an Apple store) could identify WHY/WHAT may be wrong! Prevailing literature couldn't narrow down the issue.


Thanks to all of you that reviewed this topic to see if you could help; I had somehow imagined that each burning LED would pin-point a specific problem -- but found out that it's way more complicated than that. I look forward to having the unit diagnosed and providing feedback to anyone else that may run across these symptoms.

Respectfully,

jj

Jun 13, 2015 2:01 PM in response to ~jj

"Conventional Wisdom" has been that since the Xserve was discontinued, the "Server" versions of Mac Pro Hardware differed from the standard versions only by Peripherals and Drives installed and software installed.


There have always been certain "always-on" power supplies inside a Desktop Mac, and the Mac Pro has internal LEDs that signify things, but there was never a good reference to the complete set of what those LEDs meant.


I am not sure you have discovered something unique.

Nor am I sure you have NOT discovered something unique.

Jun 13, 2015 2:58 PM in response to ~jj

THANK YOU for the EXCELLENT [re-enforcing] feedback! :-) :-) I greatly appreciate your expertise!


I spent over 10 weeks wrangling with AppleCare (5-Jan till 15-March) to discover this device’s roots and get it registered— only to be told that despite the best efforts of AppleCare and its escalations, the device remains an unknown — and modifications to Apple’s internal systems could not be made to allow the device to be registered!


I worried for MONTHS that I had acquired a defective unit — and it was only by CHANCE that I stumbled upon the document cited in my previous post; but it was that document, along with the inability of ANYONE to provide more insight (and perhaps the DVD’s manufacture date of June 2010) that allowed me to decode WHAT this device’s purpose was — and why its Serial looked as follows:User uploaded file

Jun 13, 2015 3:56 PM in response to ~jj

That serial number does not look up to anything.


But the Model number and EMC number looks up to cousins of this model. Read carefully what this expert Hardware site has to say about Hardware differences between the "Server" and the "standard" version [essentially, more RAM, different drives, Server software pre-installed, END OF LIST]


http://www.everymac.com/systems/apple/mac_pro/specs/mac-pro-quad-core-2.8-mid-20 10-nehalem-server-specs.html


.

Jun 14, 2015 5:54 PM in response to ~jj

Tee-hee.... perhaps it DID!!!! But Apple had 10-weeks and a series of escalations between 5-Jan-2015 and 15-Mar-2015 (Case #724810268; AppleCare Supervisor's Ryen & Leah) to do something about it. (I PURPOSELY contacted them EARLY ON to ensure the device wasn't reported as stolen!)


I just wish Apple would tell me the WHOLE story! I had a fantasy that perhaps it was a Gift from Apple to Steve Jobs -- because that's about the ONLY way a company would HIDE the existence of a hardware asset! (you know... Steve Jobs wouldn't take compensation -- so if a "special device" that was the direct descendant of his NEXT computer just happened to be given to Steve prior to his death-- it would have to have a "non-traceable" serial number -- wouldn't it? LOL cloak & dagger!)

Jun 14, 2015 6:21 PM in response to ~jj

Oh yeah... the disclaimer (which typically indicates Pre-Production): "This device has not been authorized as required by the rules of the Federal Communications Commission. This device is not, and may not be, offered for sale or lease, or sold or leased, until authorization is obtained. Assembled in China."

User uploaded file

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Mac Pro working but logic board LEDs on when computer off!

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