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

Oh; this is a 12-core 2.66GHz mac pro 5,1 pretty-much stock condition (no RAID or additional PCIe cards). Thanks again!

SHEEESH! CORRECTION: When the unit is in INITIAL-POWER and SHUT-DOWN.... the ***S5*** light is GREEN! (not the "S3" light as I originally posted) Thank you for your forbearance with me!

MORE INFO: When I put the unit into sleep mode, the front button pulses with a heart-beat like normal, and the “PLT RST” led burns continuous RED. (If I knew how to combine these posts... I would!!!)

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

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.pdf

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

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:

Grant Bennet-Alder: You’re assistance and perspective are INVALUABLE — and I have benefitted from your expertise both directly and indirectly HUNDREDS of times! I appreciate that you’re sticking with me here! :-)

I’ve been through the everymac.com site dozens of time; it’s a favorite! But you yourself already provided the answer: “That serial number does not look up to anything.”

That’s because it’s a PROTOTYPE; the second exterior clue is the little line below “model number and EMC number cousins” — because instead of providing a configuration summary like “MAC PRO 2.8QCX/3X1G/1TB/5770/SD-USA” — it provides BUILD REFERENCE “CFG408.”

I’ve spent 6 months searching for every answer but a PROTOTYPE — and now that’s the ONLY answer that remains! NOBODY has a device that behaves the same — and its FAR TOO COINCIDENTAL that the status lights behave PRECISELY (NOT ONE DIFFERENCE) as the Late 2009 Xserve did. Further, the unit was produced in June 2010 -- a month before the 5,1 general release... and five months before the Server release. The conclusion actually vindicates the seller, who told me from the outset that it “had previously been a server in an Apple Store.” PROTOTYPES have to be studied to be beneficial; and now it’s the collector’s turn! :-)

Oh, and BTW: My [other] Mac Pro 5,1 2.8GHz Quad Core, which coincidentally matches your everymac.com link, also has a serial tag embossed as "Model No.: A1289 EMC No.2314." Despite everymac.com's phenomenal wealth of information.... labeling doesn't always match the everymac diction.

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!)

I had posted the following "Standby State" photo on MacRumors -- but we've talked about this device enough that it seems appropriate to "double-post" here as well.

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."

Eye Candy.