I acquired a cMP5,1 recently. Everything seems to work okay except there is a problem wake up from sleep: the power LED lights up, other than that nothing seems to work, no display, didn't response to "ping" from other computer. tried resetting NVRAM/SMC, it didn't help. Is this logic board problem or power supply problem? Thanks!
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Wake up from sleep problem
- Thread starter hlyi
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Waking from sleep is a common symptom of PSU problems, but can be caused by the backplane (correct name of MP5,1 logic board) too. First step is to test a known working PSU.
@tsialex Thanks a lot for the feedback! Unfortunately, I couldn't locate anther cMP to swap PSU. Any other way or test could be done to determinate the PSU problem vs logic board problem?
If you have a logging multimeter/scope with memory, you can detected when the PSU fails to send power and mess with sleep, but it's a very time consuming job doing this way.
Diag lights on the backplane are not made for diagnosing a failing PSU, so it's useless for this problem. If you don't have the necessary equipment, I don't know of any definitive tests without exchanging parts with a working Mac Pro.
I have the same problem with my main mac pro and after i update to 10.14.5 mac go in sleep for few minutes and after white led stay on full time and computer never come back from sleep. I have to force shutdown from power button and start again. I have another mac pro with 10.14.5 as well and he sleep normal without issue. I swap PSU and same problem with main mac pro no wake from sleep and second mac pro work perfect in sleep same like before.
I mention main mac is 2x 3,46 ghz and run in 512 m.2 nvme ssd. Second mac pro is single core 3.06ghz with 256 nvme ssd. The differences is single cpu mac run on mojave 10.14.5 with fresh os installed and dual cpu mac run mojave 10.14.5 cloned from another ssd i have before. Maybe is a issue with mac osx system. I need some help pls.
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You have to diagnose what is failing, could be the backplane, CPU tray, GPU…
Since you have two Macs, make a plan of attack and start replacing parts until you find what's causing.
Software problems would show for everyone that have the same config as you have, since it's not a widespread issue, it will probably be a hardware one.
Computer's are different, i can't replace nothing maybe only GPU, second mac run with AMD R9 280X 3gb apple bios, i already swap PSU and is not any problem from there. CPU tray and logicboards are different one is 2009 and another one is 2010 and with dual and single cpu tray.
You can use a 2010 tray with a 2009 backplane, or the reverse, fans will go full RPM full time, but it's useful for diagnostics.
To be onest i don't remember but i try to replae now and i let you know later. I also try with apple gpu to be sure is not issue from there. Thanks Alex!
