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guitar guy Author

Level 2

327 points

turn computer on, no display, and fans full speed...

Hello.

I have a Power PC G5 quad running 10.5

I have the old apple cinema display with the adc to dvi adapter.

It has been running fine until....

Today, i had to unplug the display, and remove all usb attachments from the G5 and move the computer to have my room painted.

I just put it all back together, correctly, and when I power up the G5, the display does nothing, and i hear the copmuter power up, but after about 30 seconds, the fans start running full speed and don't stop.

And so without any monitor, i have to force shut down the computer (or let the fans run full speed for eternity...)

When I push the power button on the display, the power light within the button lights up, but goes dim when I release the power button. And the display never turns on.

I'm wondering what went wrong.

Any thoughts?

Thank you all!!!

PowerMac, Mac OS X (10.5.8), quad core

Posted on May 23, 2012 3:59 PM

Best reply

japamac

Level 7

24,400 points

Posted on May 23, 2012 5:12 PM

Sounds like the machine doesn't get to logic; processor function.

Start with the basics.

1- Reset the PRAM

Resetting your Mac's PRAM and NVRAM

2-Reset the SMU

How to reset the SMU on a Power Mac G5 - Apple - Support

3-Inspect for coolant leaks

PowerMac G5 Coolant Leaks/Repairs

4-Reseat the RAM

PowerMac G5 Memory Installation - YouTube

5-Reseat the graphics card

Installing Power Mac G5 Graphics Card

Of note: any diagnostic LEDs lit?

About the Power Mac G5 (Late 2005) diagnostic LEDs

View in context

18 replies

guitar guy Author

Level 2

327 points

Jul 21, 2014 3:19 PM in response to japamac

well, it happened yet again. I'm sure its time to replace the PRAM battery now. It's about 2 years old. The weird thing is that this happened last year and it just fixed itself, and has been fine for a year. It still doesn't seem like its the PRAM battery, but that's what I'm going for.

By the way, the problem is that every time i clean out the fans and put the air deflector and cover back on, the computer doesn't boot up, the keyboard is unresponsive (can't reset PRAM, and can't boot up from install disk holding the C button), and the display won't turn on. All that happens when i push the power button is that the fans start spinning slowly, as if the computer is idle (it never makes the apple sound, nor does it go through a boot up process), but after 30 seconds the fans go full speed. Still no display.

Anyway, i'm ordering the PRAM battery...

Allan Jones

Level 9

68,834 points

Jul 21, 2014 5:08 PM in response to guitar guy

Dear guitar guy,

FYI, japamac has left the forums. This is not the place to discuss reasons, of which I have only partial knowledge, but he seems gone for good. Last post was in August 2012.

He still has his web site. You might see if you can find some useful info there:

http://www.jcsenterprises.com/Japamacs_Page/All_Things_PPC.html

We all are missing his wisdom.

BDAqua

Level 10

239,363 points

Jul 22, 2014 1:55 AM in response to Allan Jones

We all are missing his wisdom.

Indeed.

turn computer on, no display, and fans full speed...