Cannot install Leopard on G4 AGP

[zappa37]

I am a cherry when it comes to Macs and all the upgrades, but here it goes.
I was given a PowerMac G4 AGP Graphics machine: 350mhz... I bought a copy of MacOSX and it installed onto the machine with no problem. I then wanted to upgrade the processor to something faster so I purchased a GigaDesign single processor Model# 7A-1800U. Everything became so much faster especially once I upgrade the RAM to 2gig.

Then I decided to get a version of Leopard to put on the machine and I received an error saying that Leopard cannot be installed on this machine. I then ran the disk repair utility and found nothing was unable to be fixed.. so I tried again... same results. Then I had the bright idea to wipe the drive and install leopard onto a blank disk (yes, I did back up the important stuff to a FW external harddrive). But again I received the same message. So I then tried to install the version of Tiger I had on it originally. Then!!!! I received the same message that Tiger could not be installed on this machine!!!!!

Now the stupid thing that I did was throw out the original processor when I had a get rid of all the legacy stuff out of my shop and out it went with alot of other stuff... now I am wondering if the giga design processor is not compatible with Tiger or Leopard without first installing useing the original processor...... what the heck can I do to get my Mac Back!!!!!!!

 

[RacerX]

Well, you've learned an important lesson... never get rid of original equipment.

I upgraded the processor on my PowerMac 8600/300, but I still have the original.
I upgraded the processor on my PowerBook G3/266, but I still have the original.
I upgraded the processor on my Beige PowerMac G3 MT, but I still have the original.
I upgraded the processor on my PowerMac G4 AGP, but I still have the original.

Third party processor upgrades aren't Apple equipment and the OS installer is only looking at your system based on it's original configuration (not your modifications).

Options? Easy... go to ebay and hope that someone is doing what they shouldn't be doing, selling their original processor from a G4 AGP.

After that, 10.4 should install fine... but 10.5 is going to require a third party hack on that system as (from Leopard's point of view) it doesn't meet the minimum requirements (no matter what upgrades you've installed). I don't know of any that support 10.5 yet.

 

[zappa37]

Thank you for responding to my post. Primarily it was more salt in the wound. However, I do know better as long as I have been working around computers.

I guess my ultimate question is... are there any tricks to at least get Tiger back on the machine using the dip switchs on the giga design chip?

I believe that the G4 I have came with a 7400 series processor, however the giga design processor is a 7A-1800U. I have also notice through reading the .pdf files that this upgrade processor seems to only accelerate the 100mhz and the 133mhz. There were no tables that reflected a 350mhz processor. (another mistake on my part purchasing). So now I am unable to set the giga design back down to original speeds.

Is there any hope? Or have I bent myself over the back of the proverbial couch!!!

 

[andychrist]

Actually, having the original processor would not help you install Leopard, as it is not supported on machines running bellow 867 MHz.

That said, there is an easy way to install 10.5, if you have a friend with a Leopard compatible PPC Mac. You can either plug your Mac's HD into your friend's drive bay or use your external Firewire enclosure in target disk mode and install right onto it from there; when you plug the HD back into your Tower it will boot up just fine from the new install.

 

[ElDiabloConCaca]

I have also notice through reading the .pdf files that this upgrade processor seems to only accelerate the 100mhz and the 133mhz. There were no tables that reflected a 350mhz processor.

I think you misunderstood whatever you read in the PDF file.

The "100MHz" and "133MHz" they refer to in the PDF document concerns bus speed, not processor speed.

Those are two, completely separate things (albeit a bit related).

Your 350MHz processor speed Macintosh computer has a 100MHz bus speed.

 

[RacerX]

Thank you for responding to my post. Primarily it was more salt in the wound. However, I do know better as long as I have been working around computers...

Is there any hope? Or have I bent myself over the back of the proverbial couch!!!

Well, your Giga Design's upgrade uses a 7447A processor on their specially designed daughter board (which is the 7A-1800U model number) and is designed to run at up to 1.8 GHz.

The problem is that no amount of dip flipping is going to change the fact that it is not the original equipment. Your original G4 (7400) processor was on an Apple designed daughter board, and that is at the heart of your problem.

Here is the thing... at this point I'm not sure that self help type of advice will be helpful any more. There comes a time when someone attempting to help themselves by seeking advice is sort of like performing self surgery.

From what you've posted so far, you've reached the point where professional (hands on) help is needed. And this is why people like me are in business to begin with... to pick up where this type of advice forum falls short. Find someone who knows what they are doing, pay them to get you back to a working system (including an original Apple G4 daughter board for your system), pick their brains for some more detailed information about your hardware and odds are you'll never need to employ someone for something like this again (and if you have to, you already have their number).

The solution to your problem has been posted, I've checked and the needed part is available on ebay at a reasonable price... the fact that you wish to avoid the solution and possibly damage your processor upgrade makes me believe that you really need to cut your losses and get a professional to look at your system.

This advice especially applies for you as you most likely are use to knowing what you are doing... which makes you more likely to damage your system further. People who consider themselves computer experts are generally the last people to seek professional help when needed. But if you can't tell the difference between the bus speed and processor speed on your system, then it might be a good idea to seek the help of someone who can get you past your current issue and help you learn more about your system.

Sorry if all that sounded harsh... I just want to avoid making the problem worse for you.