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How to re-calibrate the fans on my dual 2.0Ghz PowerMac G5?

PowerMac G4 MDD

PowerMac G4 MDD

macrumors 68000
Original poster
Jul 13, 2014
1,900
277
Hey everyone,

So I just changed out the hack-job white LED lighting system in my G5 to similar LED lights that change colors. Right after doing this, I noticed that the fan, which sits in front of the mid-section of the G5 (behind the frontal grill of the computer, right underneath the optical drive) spins much faster than before... IDK if it's some strange coincidence, but it would always run at a much lower speed. (still spins fast while idle now).

Anyway, to be safe, I still want to do a fan calibration. I know that you have to have Apple's diagnostic disc to boot from, then you select the calibration test.

Question: Is it necessary to do this test if I haven't done anything like reseated the CPUs? I just want to make sure my fans aren't running faster or slower than they need to be.

Also, WHERE do I obtain this disc or disc image? Is there a free download somewhere for this hardware diagnostic disc?

-Thanks (gosh, this frontal fan is bugging me...)


EDIT: I did the calibration test (even though it said it was not necessary) and I guess it really WASN'T necessary. Yet, this fan is still running so much faster! It's really annoying me.
 
Last edited:
gavinstubbs09 said:
I have 2.5.8 that I can Dropbox if you need it. Small download and will fit on a CD.
Click to expand...

That would be great! As far as I have seen, downloads for these things aren't really around. Do I need an account to receive the file or just a link to your shared items? (sounds like a n00b question, but I am not quite certain since I haven't used the Dropbox application itself).
 
PowerMac G4 MDD said:
Anyway, to be safe, I still want to do a fan calibration. I know that you have to have Apple's diagnostic disc to boot from, then you select the calibration test.

Question: Is it necessary to do this test if I haven't done anything like reseated the CPUs? I just want to make sure my fans aren't running faster or slower than they need to be.
Click to expand...

Apple Service Diagnostics 2.5.8 allows for a calibration to be done at any given time. 2.5.7 and below have a set list of requirements in order to allow calibration. Since you did not remove the processor you should definitely use 2.5.8.
 
Altemose said:
Apple Service Diagnostics 2.5.8 allows for a calibration to be done at any given time. 2.5.7 and below have a set list of requirements in order to allow calibration. Since you did not remove the processor you should definitely use 2.5.8.
Click to expand...

I am running 2.5.8 now. It said I didn't need calibration, however I did it anyway in hopes of it unknowingly fixing anything that COULD be wrong... I left it while I ate dinner, came back, and can see that it is STILL testing CPU 1. Why is this thing hanging?
 
PowerMac G4 MDD said:
I am running 2.5.8 now. It said I didn't need calibration, however I did it anyway in hopes of it unknowingly fixing anything that COULD be wrong... I left it while I ate dinner, came back, and can see that it is STILL testing CPU 1. Why is this thing hanging?
Click to expand...


Calibration can take 30-45 minutes depending on the machine.
 
There isn't a temp sensor you've accidentally disconnected?

I had a similar thing on my Mac Mini, found out I'd not reconnected a temp sensor when re-assembling the thing, so it ran the fan at 100% at all times as a precaution.
 
HereBeMonsters said:
There isn't a temp sensor you've accidentally disconnected?

I had a similar thing on my Mac Mini, found out I'd not reconnected a temp sensor when re-assembling the thing, so it ran the fan at 100% at all times as a precaution.
Click to expand...

I don't think I touched anything while installing the lights. Some are closer to that fan... I wonder if the lights are causing the temperature sensors on the fan to think things are getting hotter... then again, the lights barely give off heat.

----------
Altemose said:
Calibration can take 30-45 minutes depending on the machine.
Click to expand...

Yeah, it ended up finishing with no issues... that one fan is still running fast though.
 
PowerMac G4 MDD said:
I don't think I touched anything while installing the lights. Some are closer to that fan... I wonder if the lights are causing the temperature sensors on the fan to think things are getting hotter... then again, the lights barely give off heat.
Click to expand...


Have you tried seeing if both CPUs have a similar temperature? You can view this in iStat Menus or Temperature Monitor. Within 10 degrees Fahrenheit of each other is normal.
 
Just that one fan is running fast - the one that is on the same bracket with the internal speaker?
I wonder if the thermistor (temp sensor) might be an issue?
Open your side cover, then look on the front edge of the shelf that divides the PCI slot area from the logic board. If you look carefully behind the front grill on that front shelf edge, there's a small black bracket. There's a small temp sensor that should be clipped to that bracket. The little cable attaches to a connector on the logic board almost directly behind it. That cable is only about about an inch long, and may just need to be reseated, and the thermistor/sensor just feeds through that small bracket - that end can be left loose, too, because it's really short. Good luck on reseating that connector without pulling the logic board out.

If you added some LED lighting behind the front grill, you may have inadvertently moved that cable, maybe even unplugged it.
 
Altemose said:
Have you tried seeing if both CPUs have a similar temperature? You can view this in iStat Menus or Temperature Monitor. Within 10 degrees Fahrenheit of each other is normal.
Click to expand...

The CPU temperature has not changed since I purchased this Mac; It's just this dang fan. Right now A is at 116F and B is at 99F. (with this Webkit page open and iChat and Mail hidden)

----------
DeltaMac said:
Just that one fan is running fast - the one that is on the same bracket with the internal speaker?
I wonder if the thermistor (temp sensor) might be an issue?
Open your side cover, then look on the front edge of the shelf that divides the PCI slot area from the logic board. If you look carefully behind the front grill on that front shelf edge, there's a small black bracket. There's a small temp sensor that should be clipped to that bracket. The little cable attaches to a connector on the logic board almost directly behind it. That cable is only about about an inch long, and may just need to be reseated, and the thermistor/sensor just feeds through that small bracket - that end can be left loose, too, because it's really short. Good luck on reseating that connector without pulling the logic board out.

If you added some LED lighting behind the front grill, you may have inadvertently moved that cable, maybe even unplugged it.
Click to expand...

Yep, it's the one on the same bracket as the external speaker. When I wake the computer up, it begins to spin at the speed it used to rotate at before putting in the LED lights, but after 5 seconds, it speeds up. I'll go ahead and inspect it as you have said. Thanks for the info; I will update you if something happens or doesn't happen.
 
DeltaMac said:
Just that one fan is running fast - the one that is on the same bracket with the internal speaker?
I wonder if the thermistor (temp sensor) might be an issue?
Open your side cover, then look on the front edge of the shelf that divides the PCI slot area from the logic board. If you look carefully behind the front grill on that front shelf edge, there's a small black bracket. There's a small temp sensor that should be clipped to that bracket. The little cable attaches to a connector on the logic board almost directly behind it. That cable is only about about an inch long, and may just need to be reseated, and the thermistor/sensor just feeds through that small bracket - that end can be left loose, too, because it's really short. Good luck on reseating that connector without pulling the logic board out.

If you added some LED lighting behind the front grill, you may have inadvertently moved that cable, maybe even unplugged it.
Click to expand...

Okay, well I opened it up, checked out the thermal sensor, and everything seemed okay with it. I then put a bedroom fan to cool off the unit to simulate a cold start-up. I disconnected the plug in my lights in case they were creating too much extra heat. I powered the machine on... and the issue persists. It's odd; maybe this is some unfortunate coincidence? It would be funny to hold an ice pack on the thermal sensor and see if it even works xD. I don't feel like disassembling my set-up again today, though.
 
gavinstubbs09 said:
I have 2.5.8 that I can Dropbox if you need it. Small download and will fit on a CD.
Click to expand...
I just put in a new mother board and need to re-calibrate the fans. G5 2.0Ghz. Don't have drop box.
Anyway to get this file...computer working but fans are a little noisy.
[doublepost=1557509708][/doublepost]
Earl Tyo said:
I just put in a new mother board and need to re-calibrate the fans. G5 2.0Ghz. Don't have drop box.
Anyway to get this file...computer working but fans are a little noisy.
Click to expand...
 
The ASD 2.5.8 is getting harder to find...
I did find THIS page - https://www.loremipsum.info/2019/03/apple-service-diagnostics-mac-test-pro/
Be aware that there is some problems on that page.
The 2.5.8 version is not correct on that page, (downloads version 2.1.5, which is wrong for you) but the 2.5.7 version should do exactly what you need for the calibration.
There were 4 different G5s with 2.0 GHz processors. The older 3 will all use the 2.5.8 (2.5.7) version, but there was also one 2005 version 2.0 GHz which uses the ASD 2.6.3. That one appears on that same download page, just in case that's the one that you have.
 
DeltaMac said:
The ASD 2.5.8 is getting harder to find...
I did find THIS page - https://www.loremipsum.info/2019/03/apple-service-diagnostics-mac-test-pro/
Be aware that there is some problems on that page.
The 2.5.8 version is not correct on that page, (downloads version 2.1.5, which is wrong for you) but the 2.5.7 version should do exactly what you need for the calibration.
There were 4 different G5s with 2.0 GHz processors. The older 3 will all use the 2.5.8 (2.5.7) version, but there was also one 2005 version 2.0 GHz which uses the ASD 2.6.3. That one appears on that same download page, just in case that's the one that you have.
Click to expand...

Go here.
 
B S Magnet said:
Go here.
Click to expand...
Unfortunately, "Wayback" archives don't always take you where you expect. It's one of those sites where I did already check. Stlll no 2.5.8 available there, so it seems.
Again, the slightly older ASD 2.5.7 version seems to be there, and should do the job, too.
 
Last edited:
DeltaMac said:
Unfortunately, "Wayback" archives don't always take you where you expect. It's one of those sites where I did already check. Stlll no 2.5.8 available there, so it seems.
Again, the slightly older ASD 2.5.7 version seems to be there, and should do the job, too.
Click to expand...

Heck, that’s really unfortunate. I bookmarked that right when the source got yanked a few months ago.

::checks just to be sure::

No, 2.5.8 is still there!
 
You got me on that.
I thought that I was pretty good at searching, but that wayback archive throws me for a loop...
How in the world did you actually find that? Even when I was looking at those dreamsupport site listings of files, I couldn't figure out how to find that 2.5.8, and single it out from everything else -- but you made it look easy.
For some strange reason, my normal search tricks just did not work.
Is there some kind of guide on that wayback archive site that explains how to look for sites, then files, or whatever works?
I didn't see anything obvious, and my weak attempts to even find the ASD 2.5.8 failed horribly.

(Maybe this is off topic, eh?)
 
DeltaMac said:
You got me on that.
I thought that I was pretty good at searching, but that wayback archive throws me for a loop...
How in the world did you actually find that? Even when I was looking at those dreamsupport site listings of files, I couldn't figure out how to find that 2.5.8, and single it out from everything else -- but you made it look easy.
For some strange reason, my normal search tricks just did not work.
Is there some kind of guide on that wayback archive site that explains how to look for sites, then files, or whatever works?
I didn't see anything obvious, and my weak attempts to even find the ASD 2.5.8 failed horribly.

(Maybe this is off topic, eh?)
Click to expand...

Meta, but not entirely off-topic, given how locating abandonware and granular updates requires having good searching skills. :)

This also happens to be something I’m fairly good at doing — even in spite of the utter SEO-caused corruption of searches.

Basically from the original link I have bookmarked, I clicked on 2.5.8 and found how, like you, it didn’t come up. So I backtracked to the bookmarked page, clicked on the earliest iteration from around 2012, and then clicked through to the 2.5.8 link, to find that it had been preserved for posterity a total of once (mercifully) in around 2014, I think.
 
THAT download from wayback, unfortunately, appears damaged, and although it seems to open, won't give me a usable image to burn to a CD - maybe it will work for someone else, but not for me.
(I guess it's a good thing I have an old copy of the image that I originally downloaded from Apple when I was working as a tech. THAT one I can use. I was just trying to help the poster to find a good link to a usable download. Seems unsuccessful at this point.
 
DeltaMac said:
THAT download from wayback, unfortunately, appears damaged, and although it seems to open, won't give me a usable image to burn to a CD - maybe it will work for someone else, but not for me.
(I guess it's a good thing I have an old copy of the image that I originally downloaded from Apple when I was working as a tech. THAT one I can use. I was just trying to help the poster to find a good link to a usable download. Seems unsuccessful at this point.
Click to expand...

Oh no. I’m sorry!

Putatively, the first link on this page’s conversation (a Rossmann forum page) is a possible lead for the 2.5.8 image, though it will need to be manually selected as the specific file you want to download. Beyond that, I don’t know where else to look. For the original poster, good luck!
 
DeltaMac said:
Unfortunately, "Wayback" archives don't always take you where you expect. It's one of those sites where I did already check. Stlll no 2.5.8 available there, so it seems.
Again, the slightly older ASD 2.5.7 version seems to be there, and should do the job, too.
Click to expand...
gavinstubbs09 said:
I have 2.5.8 that I can Dropbox if you need it. Small download and will fit on a CD.
Click to expand...
Earl Tyo said:
I just put in a new mother board and need to re-calibrate the fans. G5 2.0Ghz. Don't have drop box.
Anyway to get this file...computer working but fans are a little noisy.
[doublepost=1557509708][/doublepost]
Click to expand...
Need to recalibrate the fans after replacing mother board on G5 2.0 from 2005. Link received does not work.
Please need help!!
 
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