MacPro 3.1 doesn't start, but starts with a "Hack".
crwdns2934249:0crwdne2934249:0:
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Yesterday I wanted to book up the old MacPro 3.1 (Early 2008)
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The last time it ran was about a month ago.
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It only serves as a video watching system by now.
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Yesterday I wanted to book up the old MacPro 3.1 (Early 2008) The last time it ran was about a month ago. It only serves as a video watching system by now.
=== The Problem: ===
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Nevertheless, it didn't start. No main fans moving. The Graphics card fan moved.After about 0.5-1.5 seconds it turned off. I tried several times always the same.
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Nevertheless, it didn't start. No main fans moving.The Graphics card fan moved.
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I had only one problem with it during a cleanup once in the past, where it didn't start.I think it was a loose graphics card at the time, so I opened and cleaned him.Wasn't that dirty to be honest.
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After about 0.5-1.5 seconds it turned off. I tried several times always the same.
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Still not working, a few searches and the usual suspect is the ***Power Supply Unit*** (PSU). I removed it and a visual inspection suggests it's fine. Capacitors and Coils look fine. Cleaned it, put it back together still nothing.
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I had only one problem with it during a cleanup once in the past, where it didn't start.
-
-
I think it was a loose graphics card at the time, so I opened and cleaned him.
-
-
Wasn't that dirty to be honest.
-
-
Still not working, a few searches and the usual suspect is the ***Power Supply Unit*** (PSU).
-
-
I removed it and a visual inspection suggests it's fine. Capacitors and Coils look fine.
-
-
Cleaned it, put it back together still nothing.
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While reading about trouble shooting,
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I noticed a red blinking light. ***CPU A OT*** and ***CPU B OT***.
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I tried the button next to it and the ***SYS_RES*** button as well.
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At some point I did hear the startup sound, so I plugged the monitor back in and still the
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same behaviour as above.
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While reading about trouble shooting, I noticed a red blinking light. ***CPU A OT*** and ***CPU B OT***.I tried the button next to it and the ***SYS_RES*** button as well. At some point I did hear the startup sound, so I plugged the monitor back in and still the same behaviour as above.
=== ***The "Hack":*** ===
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However, after several trials I figured out I can press the power on button several times and hold it. After 3-4 times, the two LEDs ***CPU A OT*** and ***CPU B OT*** will light up permanently. Once that happens the next time the MacPro starts fully functional, but with the fans on full blast. I didn't find this behaviour documented in the manual, but might have missed it.
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However, after several trials I figured out I can press the power on button several times
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[link|http://tesselator.gpmod.com/_Text/MacPro_Service_Manual.pdf|Mac Pro Service Manual]
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and hold it. After 3-4 times, the two LEDs ***CPU A OT*** and ***CPU B OT*** will light up permanently.
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Once that happens the next time the MacPro starts fully functional, but with the fans on full
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blast. I didn't find this behaviour documented in the manual, but might have missed it.
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-
[link|http://tesselator.gpmod.com/_Text/MacPro_Service_Manual.pdf|Mac Pro Service Manual|new_window=true]
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I downloaded the hardware diagnostic tool [link|https://github.com/upekkha/AppleHardwareTest|(Link)|new_window=true] and put it into
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I downloaded the hardware diagnostic tool [link|https://github.com/upekkha/AppleHardwareTest|(Link)] and put it into
***/System/Library/CoreServices/.diagnostics*** and ran it.
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No warnings. The extended test ended as well with "***No trouble found***"
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It took 1.5h, so I think the PSU is fine.
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I'm now running the test again with full RAM installed, out of desperation.
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No warnings. The extended test ended as well with "***No trouble found***" It took 1.5h, so I think the PSU is fine. I'm now running the test again with full RAM installed, out of desperation.
=== Questions: ===
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I don't know how to proceed now.
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I suspect it's some kind of error in the thermal sensors.
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They're plugged in correctly as far as I can tell.
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I didn't remove the CPU coolers as I don't have thermal paste.
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-
Is there a way to confirm one of the sensors are at fault?
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-
Also note they only are lid up after the "Hack", so maybe this is just a special mode?
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I don't know how to proceed now.I suspect it's some kind of error in the thermal sensors. They're plugged in correctly as far as I can tell. I didn't remove the CPU coolers as I don't have thermal paste. Is there a way to confirm one of the sensors are at fault. Also note they only are lid up after the "Hack", so maybe this is just a special mode?
MacPro 3.1 doesn't start, but starts with a "Hack".
crwdns2934249:0crwdne2934249:0:
Yesterday I wanted to book up the old MacPro 3.1 (Early 2008)
The last time it ran was about a month ago.
It only serves as a video watching system by now.
=== The Problem: ===
Nevertheless, it didn't start. No main fans moving. The Graphics card fan moved.
After about 0.5-1.5 seconds it turned off. I tried several times always the same.
I had only one problem with it during a cleanup once in the past, where it didn't start.
I think it was a loose graphics card at the time, so I opened and cleaned him.
Wasn't that dirty to be honest.
Still not working, a few searches and the usual suspect is the ***Power Supply Unit*** (PSU).
I removed it and a visual inspection suggests it's fine. Capacitors and Coils look fine.
Cleaned it, put it back together still nothing.
While reading about trouble shooting,
I noticed a red blinking light. ***CPU A OT*** and ***CPU B OT***.
I tried the button next to it and the ***SYS_RES*** button as well.
At some point I did hear the startup sound, so I plugged the monitor back in and still the
same behaviour as above.
=== ***The "Hack":*** ===
However, after several trials I figured out I can press the power on button several times
and hold it. After 3-4 times, the two LEDs ***CPU A OT*** and ***CPU B OT*** will light up permanently.
Once that happens the next time the MacPro starts fully functional, but with the fans on full
blast. I didn't find this behaviour documented in the manual, but might have missed it.
[link|http://tesselator.gpmod.com/_Text/MacPro_Service_Manual.pdf|Mac Pro Service Manual|new_window=true]
I downloaded the hardware diagnostic tool [link|https://github.com/upekkha/AppleHardwareTest|(Link)|new_window=true] and put it into
***/System/Library/CoreServices/.diagnostics*** and ran it.
No warnings. The extended test ended as well with "***No trouble found***"
It took 1.5h, so I think the PSU is fine.
I'm now running the test again with full RAM installed, out of desperation.
=== Questions: ===
I don't know how to proceed now.
I suspect it's some kind of error in the thermal sensors.
They're plugged in correctly as far as I can tell.
I didn't remove the CPU coolers as I don't have thermal paste.
Is there a way to confirm one of the sensors are at fault?
Also note they only are lid up after the "Hack", so maybe this is just a special mode?