you will need to chech rom to see if it has enough room for the apple EFi in order to run in osx, you can run it in PC mode as long as you set it up before you insert the card, switch on straight to PC rather than boting into OSX

Hi, Sorry it is not good news, 5 Beeps from the AMI bios, that is definatly a motherboard problem, it is complaining, a quick fix may well be to upgrade your CPU, in this system you are very limited as to what you can put in there CPU wize. In theory you can, MEM and Bios will play a part, as well as heat, can the system handle an upgrade, make sure there will not be problems with Heatsink, this must fit 100% I would suggest buying or repairing your motherboard. The upgrade will only be a temp fix. Where as motherboard will last much longer. if you have a CPu knocking about that you can use , it may be worth the effort.

The Palm rest needs to be removed to check for short direct to board, I have seen this often on this model, usually in location beneath left hand/palm area, you also need a battery. Accidental shut down, due to sudden loss of power, will result in more unneccesary damage (hard drive), causing further problems, would be worth checking beneath palm rest first before you invest in a new battery, only ever buy original battery & power supply, never use compatable, I think this unit is beyond tilting, an empty battery bay should not cause problems as long as nothing else gets in there.

Due to age. the palm rest has a tendancy to move/stretch change shape , this may well now be occasioanlly shorting the logic board, if my mem servs me right, try logic board location below where your left palm would be, further insulation may get things back to normal, if this is the problem don not just leave as some damage can not be corrected in this area due to logic board being of multi layered construction

Hi, the Nvidea 8800 is only in the 24" imac, the Nvidia 8800 is also nothing like the cards from the other models, if you wish to upgrade your 24" imac (the one with the Nvidia 8800) you have no choice but to replace it with the exact same video card another nvidia 8800. Several reason, if you are interested i will spell them out in my next post. Can I also just add, if you dont understand what you are taliking about might I suggest that you do not offer advice as it is most off putting, the earlier White Imac had onboard video built onto the motherboard , that is all of them except the 24" 2.1ghs core duo this was fitted with an MXM card either the Nvidia 7300 or 7600. The aluminium 20" and 24" core duo also have MXM cards but once again not all of them, the odd one was onboard graphics, I have managed to swap cards amongst most of these , except the nvidia 8800 , as the nvidia 8800 was a unique style of MXM, ( all the others were MXM II), I am at this moment in time trying to mod a newer version Nvidia...

If there is an Nvidia 8800 in your machine , then that is the only card that will go into it, I have had all of these imacs, they have different fittings for different cards, any upgraded card will require a flash with the relevent EFi, it may be a wise idea to check the size of the bios on the card first as the EFI requires 1meg most cards are fitted with a 512 chip, this is also possible to exchange, but none of this is easy.

I don't know if you have noticed but it appears to be the same block diagram for all of the models, am sorry I don't trust them and second $30 a pop seems a lot of money, the diagrams are out there some were it is just finding them, there are a few China sites with them unfortunately I can not understand to navigate my way around, i have been going through the manual page by page taking screen shots, in an attempt to get the full thing, http://wenku.baidu.com/view/273a40eff8c7... if any one can help me load this up in English I would be very greatful

Yes you can upgrade, your card, for best results stick to the options offered for your model Update: the correct discription for the 24" Imac Nvidia 8800 GS is MXM HE, I do believe that you can now get a Nvidia 9800 GTX & a Nvidia GT280, both of these are the MXM HE type, I am guessing that as long as there bios is big enough to take the 8800 GS EFI firmware, then that could be an upgrade route, the card would report a slower clock speed (due to the 8800 EFI firmware) , but am pretty sure it will run ok , I no loger possess this version of the Imac , but would be very tempted to give it a try, you would already need to have windows on there so you were able to update the card, I am pretty sure trying to install this with a faulty card woud be a recepie for disaster. You could always increase the bios size with a 1 meg bios chip, but again am pretty sure the original will be big enough to hold both the Bios and the EFI.