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Powermac G5 2.0ghz wont boot fans go ultra fast

T

therealnph

macrumors newbie
Original poster
Oct 31, 2018
3
0
hi all new to the forum, so i got 4 powermac g5s for like 20 bucks took them all apart and cleaned, added thermal paste, pads,. grease for the disc drive ect, they all worked great except for the 2.0ghz model,

when i turn it on i hear the chime, shortly after the fans go into high gear and its stuck on the apple logo. after some searching i find out there is a problem with these models and their thermal sensor and it needs the apple service disc ASD 2.5.8.dmg so i downlaod it burnt the image to a disc put it in the 2.0ghz g5 hold option when turning it on and i am led to a password which i dont know. ive tried removing ram and adding more ram and trying to reset PRAM but it does nothing fans kick into high gear with no chime when holding down command option p + r , i held it for about 2mins to no avail. password is still there.. any ideas? thanks in advance
btw ive tried the hard drive in another G5 and it booted no prob
 
eyoungren said:
It sounds like maybe you have a firmware password preventing you from booting from an optical disk.

Does this look like it may be the case?
https://support.apple.com/en-us/HT1352

And a solution if so… https://scacinto.wordpress.com/2009/02/03/reset-open-firmware-by-removing-all-ram/
Click to expand...

doesnt work )=,i think that is for iMac G5 (flat panel)
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AL1630 said:
Sounds like it has a firmware password on it. I'd google how to remove it on that specific model.
Click to expand...
i have been looking cant seem to find a way so far
 
You need to change the amount of RAM in the machine (add or remove a stick) and then reset the PRAM at least three times in a row. (Keep holding CMD+OPT+P+R, let it chime three times). This should do the trick, I've had to do it on my DP 2GHz G5 as well.
 
ifrit05 said:
You need to change the amount of RAM in the machine (add or remove a stick) and then reset the PRAM at least three times in a row. (Keep holding CMD+OPT+P+R, let it chime three times). This should do the trick, I've had to do it on my DP 2GHz G5 as well.
Click to expand...
i have done that, atleast 10 times with no result.. The computers fans just spin at ultra speed and no chime , if i dont hold cmd+opt+p+r it does chime.
the fans spinning ultra fast, could be another problem(like the heat sensor i mentioned earlier?) wouldn't it just let me boot into mac os without prompting me for a FW password? like i said i put the hard drive in another G5 computer and it booted mac os x just fine.
 
therealnph said:
i have done that, atleast 10 times with no result.. The computers fans just spin at ultra speed and no chime , if i dont hold cmd+opt+p+r it does chime.
the fans spinning ultra fast, could be another problem(like the heat sensor i mentioned earlier?) wouldn't it just let me boot into mac os without prompting me for a FW password? like i said i put the hard drive in another G5 computer and it booted mac os x just fine.
Click to expand...

It sounds like the G5 is experiencing hardware failure and the process of removing / changing RAM and resetting the PRAM isn't going to work until the machine can successfully pass the Power On Self Test again.

You could try removing one of the CPUs (if it is a Dual Processor machine) - The top slot must have a working CPU to boot. Also remove all but the minimum amount of RAM (maybe 2x 256 or 2x 512) - remembering that these Macs require RAM to be installed in matching pairs in order to boot. On the Dual-Proc machines, the matching RAM starts from the center two slots and continues outwards. (i.e. match slots D+E, C+F, B+G, A+H).

Once you've cleared the firmware password using the method @ifrit05 describes then you should be able to hold option and boot off the Apple Service Diagnostics disc to re-calibrate the CPU(s) and run through the hardware tests.

Have a read through this Apple support article to understand how the password protection works;

Setting up firmware password protection on PowerPC-based Macs
https://support.apple.com/en-us/HT1352

Not having used this before, I just tried the firmware password feature on my PowerBook G4 12" by popping the Tiger retail DVD in and running the Firmware Password Utility which is located in /Applications/Utilities on the disc. I can confirm that it's not possible to zap the PRAM, boot off a disc, bring up the multi-boot selector or do anything with Open Firmware without entering the firmware password.

Normal booting is fine however and I was then able to use the same Firmware Password Utility to remove the firmware password. It just asked for my admin password and that was that.

If the RAM change + PRAM reset method doesn't work, you would need to move the hard drive into another Mac, boot the drive into single user mode, enable the root login, set a root password and shut down. You can then reinstall the drive into the G5, boot up as normal and login as root when the password is requested (or log out of the default user if it boots straight to the desktop and login as root using the "Other..." user option). You should then be able to run the Firmware Password Utility, entering your new root password to switch the password protection off.
 
Mine did exactly the same, prior to that the date on the mac was flagging up it was before 2001, my immediate thought was an issue with the motherboard battery. When I reset to try again, again loud fans but not getting past the Apple logo. Have ordered a new battery. Will let you know if this works when it arrives.
 
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Deadeyeshark said:
Mine did exactly the same, prior to that the date on the mac was flagging up it was before 2001, my immediate thought was an issue with the motherboard battery. When I reset to try again, again loud fans but not getting past the Apple logo. Have ordered a new battery. Will let you know if this works when it arrives.
Click to expand...
Any news_ Mine started today doing the same
No startup chime, won"t respot to cmd opt p+r just black screen and loud fans after few seconds...
 
Do you see the front panel power LED? Is it flashing at all, or just on (no flashing)?

Be sure to try reseating the video card.
 
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