I recently acquired a 24" intel core 2 duo imac (2.16 processor, NVIDA 7600, 1gb ram - I believe it is the late 2006 model)

I purchased this imac knowing that the hard drive had died. I replaced the faulty hard drive with a 500gb western digital sata drive. The computer looks in good shape both internally and externally.

Everything appears to work - the optical drive, hard drive, graphics, start up chime etc

Here is the problem

When I try to install OSX from the supplied discs that came with the computer I get the following symptoms

1) The computer boots to a white screen with grey apple logo
2) The loading of the installation discs commences (little spinning logo under the grey apple)
3) After about 2 minutes, the spinning icon stops and the computer freezes - therefore no installation of OSX can take place.

So, I thought I would try to install OSX86 on it and I have managed to install both Kalyway 10.52 and idebian 10.55 with partial success

This is what happens

1) With both Kalyway and idebian, I am able to load the installer and get to the point of formatting the drive (in GUID - haven't tried MBR) At this point, I seem to have full graphics resolution. The installation goes as smoothly as it would on a PC.
2) Installation completes and I am able to boot up into OSX, but in very low graphics resolution (1024x768 only, no quartz etc). There is also no sound, but wireless internet works.

In order to boot into OSX, I have to use the efi 132 boot disc which allows me to choose the partition to boot from. If I try to boot the computer without efi 132, I get similar syptoms to those I described above - white screen, grey apple logo, os starts to load as indicated by the spinning icon under the apple, then the computer freezes...

I have also restored the retail disc to a partition on the drive, booted up with efi 132 and have then been able to install the retail version of OSX, but again only in low graphics mode with no sound.

I have also been able to install winxp natively (ie no boot camp) and ubuntu linux...but again only in a low graphics mode, (interestingly there is sound with both ubuntu and winxp)

My thought is that somehow the efi boot rom on the imac is corrupt. I have managed to establish that there is information there (serial number, boot rom revision, SMC number etc) by entering the efi shell with rEFIt but I have no clue what I am doing in that rEFIt environment and whether or not I can edit/fix what might be a corrupt efi using rEFIt.

Other things - all the key commands (that I know) seem to work - the computer chimes, you press cmd -option, you can choose the drive to boot from, cmd-c, it will boot from the cd, cmd-option-p-r, resets the NVRAM, cmd-d starts the apple diagnostic disc if inserted (which detects no problems with the computer). I have swapped memory modules - replacing the 1gb with 4gb ram, I have reset the SMC by holding the power switch in while I reconnect the power cable, I have booted the computer with no hard drive, no mouse, no keyboard connected...all to no avail. I have also try apple's boot rom restore discs which are downloadable from their site (I tried version 1.4 and 1.6 of these discs but nothing happened when I tried to use them per the instructions on apple's site)

Currently where I am at is
1) I can boot into OSX with low res graphics and no sound using efi 132
2) I cannot install retail OSX from the DVD but I can if I restore the files to a seperate partition and then boot from efi 132
3) If I try to upgrade either OSX86 or the retail OSX via software update, I end up with a black screen

Questions:

1) Why am I able to install winxp and ubuntu natively but not OSX, and why only in this low resolutin graphics mode?
2) When I install OSX86, I get full resolution graphics during the install procedure but only low res/no sound after the OS is installed - does anyone have an insight as to why this might be?
3) Is there a way to check if the efi boot rom is corrupt on the imac and if so is it possible to fix it? (If anyone knows the answer to this and can help, I would appreciate it if could be explained as simply as possible for me)
4) Is this an efi boot problem or could it be something else?

I am baffled by all of this. The computer seems to be fine, all the components seem to work.

I 'think' this is something to do with efi and the way the computer boots initially (but I have no expertise in troubleshooting this)

Does anyone have any suggestions? Am I completely on the wrong track here?

Can anyone please help?

hey, did you try to download a leopard RETAIL dvd off of the net? perhaps the disc u have is faulty while you are booting from the dvd hold down apple + V that will get it in to verbose mode perhaps you will see what the hell is wrong

I have original install discs for the imac (10.4.7) and also retail leopard 10.5 and an intel imac install disc (10.52)

As I mention in my post, the installer begins OK but seems to get stuck just before you reach the screen that asks you to choose which language. However, if you boot the mac with an efi 132 disc, it is possible to do a full install but there is no sound and only low resolution graphics

I will try to boot in verbose mode and see where it stops. I have a feeling that there is something within the efi chip that is not allowing OSX to see the files it needs to in order to boot correctly (I wish I could explain this better but my knowledge of the boot code for efi/osx is not good)

I have a hunch that the previous owner of this mac may have done something to the efi chip by installing boot camp but I dont know this for sure (and if this was so wouldnt a replacement hard drive - which I have done - fix this problem?)

If anyone knows how to re-program or flash the efi chip on an intel imac, I would be most grateful if you can let me know

lol im not that familiar with macs im just a starter
starting to know about this stuff but it does sound like a hardware problem
did you try calling apple helpline 1-800-MY-APPLE it free they will try and help you

Calling apple or taking it for 'genius' to look at is not an option because I already know what they will say.
I want to see if its possible to fix by bypassing the expensive apple repair shop route

lol i noe what you mean u should try google it solves most of my problems =D

This is one that requires a bit more than looking on google

I'll keep my fingers crossed that someone who knows something about EFI will pick up on this thread

Thank you for your comments

i would repost that post on other forums try insanelymac thats a good site