iMac G4 Doesn't Recognize Optical Drive

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iMac G4 Doesn't Recognize Optical Drive

My little brother bought an old iMac G4 off eBay about six months ago, against the recommendations of my parents and I who told him he should save until he could afford a slightly better machine. He's been improving it here and there when his savings from lawn mowing and birthday has allowed and his latest investment was the 10.5 operating system. When we went to install on the G4, my brother was shattered to find that the machine wouldn't support it. I investigated and found the problem was due to the G4's 800mHz processor. Not a component he could easily switch out. So after a quick flick around, I found another G4 that I considered could actually be a legitimate investment, given the parts we had. The seller claimed that it was perfectly fine, only lacking a working optical drive and hence, also an operating system. Both of which we had.

The second G4 arrived last week and I successfully switched the working optical drive from the old G4 with the "broken" one. Just to make sure I wouldn't lose the screws holding it all together, I installed the "broken" optical drive into the old G4 as well. Then I went to install Leopard. The new G4 has a 1GHz processor and it recognised the Leopard install DVD at boot. It presented the loading screen with the Apple sign and the rotating loading wheel, but wouldn't progress past this. Every time we tried to boot from the install DVD, it would present this screen for around a minute and then the Apple sign would be replaced by a prohibited sign. The booting process never got any further than this. I talked to a few people and ended up installing Leopard via target mode, assuming there was something a little sus with the harddrive which would be resolved once the OS was in place. But wherever the problem lies, it still remains. The G4 now boots successfully from the harddrive and operates fine, but refuses to recognise the optical drive. Here is my chain of reasoning:

- The optical drive in the G4 is not at fault. We know this because it operated fine in my brother's first machine.

- The hard drive is not at fault. We know this because the OS installed and now boots and operates without problem.

- The OS is not at fault. We know this because I performed an almost identical installation (minus target mode) using the same install DVD only days before on a G5.

- My installation work is not at fault. We know this because I performed an identical installation of the "broken" optical drive in the old G4. An interesting side note: the "broken" drive is working fine in the old machine. It is not as broken as the eBay seller thought.

I don't know a whole lot about computers. Most of what I learn is from trial and error problem solving like this. My question is: where does the problem lie?

iMac

Posted on May 6, 2012 12:48 AM

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Answer 1

May 6, 2012 9:18 AM in response to Kid12

If both drives work in the older computer and malfunction in the newer one then it probably means there's something wrong with the computer itself.

I did some searching and found a website that concerns replacing and upgrading the parts in the iMac G4:

http://www.xlr8yourmac.com/systems/iMac_g4/imacg4_takeapart.html

One of the footnotes suggests that the DVD drive must be designated as the master and the hard drive must be designated as the slave. Maybe the criteria isn't being met in the newer machine.

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Answer 2

Jeff

Level 6

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May 6, 2012 10:11 AM in response to Kid12

"One of the footnotes suggests that the DVD drive must be designated as the master and the hard drive must be designated as the slave."

That was a reader-provider comment, concerning the master-slave designation. As was pointed out, the typical configuration is to have the HDD set as Master and the ODD set as slave, when these two types of drives occupy the same bus.

"The second G4 arrived last week and I successfully switched the working optical drive from the old G4 with the "broken" one... My installation work is not at fault. We know this because I performed an identical installation of the "broken" optical drive in the old G4. An interesting side note: the "broken" drive is working fine in the old machine."

What brand of hard drive is installed in the 1 GHz iMac? If it had been replaced at an earlier time and it's a Western Digital, the jumper may be set to "Single," for a Standalone drive. That would prevent the optical drive on the same ribbon cable from being recognized. If that's not the problem, I'd inspect the Ultra-ATA ribbon cable for damage and replace it with another.

"The new G4 has a 1GHz processor and it recognised the Leopard install DVD at boot. It presented the loading screen with the Apple sign and the rotating loading wheel, but wouldn't progress past this. Every time we tried to boot from the install DVD, it would present this screen for around a minute and then the Apple sign would be replaced by a prohibited sign."

Are you using a retail/universal installer disk for Leopard, or is it the Restore disk for another model Mac?

On a completely unrelated note, did you remove the old thermal paste and apply new paste, before reassembly of the motherboard/bottom housing?

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