iMac Motherboard Failure??

[rsmith]

Here's a confusing situation. My iMac DV (80 mbhd/768 mb RAM) was running on OS X. We may have had a power surge (not sure) and afterward that firewire ports are not working. No devices can be found when attached to the ports either in OS X or 9.

As a last resort, I reformatted my drive and reinstalled both OS X and 9. Firewire is still dead but now OS 9 works great but X won't install properly - it takes forever and when it finally runs, windows and file menus take literally several seconds to open. You can actually see them resize! OS 9 is ok, but I can't make OS X install.

Any suggestions? The hard drive doesn't show bad blocks or any other problems. Does OS X use different motherboard resources that could have been affected by a board problem? I'm at a loss...

 

[coolsoldier]

You might have a minor RAM problem (OS X uses a lot more RAM than 9). If your computer will boot at all, an all-out motherboard failure is unlikely.
The FW unit may have been fried though.

 

[rainman::|:|]

iMac motherboards are remarkably contained, since they have so many different systems. My modem died a while ago, and it was the only thing affected... the same thing probably happened to your system. I think there are places to get upgraded motherboards, the benefit is that it's a much faster processor, downside is cost... not sure if you can get a replacement motherboard tho...

pnw

 

[rsmith]

additonal issues w/imac

Now the iMac won't even start up in OS 9. When you get to the startup screen w/the blue bar, it hangs up and after about 2 mins. of the circular cursor spinning, the cursor turns into a bomb and it locks up. It does the same thing with a boot cd.

 

[TMA]

A few things I would try, probably wont work but worth giving a go...

Check RAM is installed ok. Remove and re-install. Also check all other connections that you have easy access to without having to rip the case apart.

Reset the motherboard. (should be a switch somewhere internally but i'm afraid I don't know where) Zap the PRAM. Not done this for years so I don't know the key combo or if it's still something that can be done.

Try booting up from a diagnosis CD or any other Mac OS disks you can get your hands on. Then run Disk Utility (and/or other disk utilities) on your HD if you get it to load.

When it bombs on startup make a note of any numbers/codes displayed and if you hear a number of 'chimes' count them. Look them up on the net.

Good luck and let us know how it goes!

 

[daveg5]

partition the first 7.99 GB for osx installation