Longtime Apple Tech with superdrive-inspired "techie-block"

Question

Greetings all,
I'm an Apple Tech and have been working on Apples for 24 years now (scary to be doing ANYTHING that long!) and occasionally I come across something I can't solve right away. I never give up and find that it is sometimes tough without a current ASD disc (I gave up my recertification/Apple affiliation because my certs (4 of them) used to be $90 total for renewal, then they went WAY up. Now, I do my best and I do very well 99% of the time. I'm in that 1% right now and wondering if this is a problem any of you may have run into. I have a 2007 iMac Alum. I am upgrading for a client. Put a nice new 1TB HD in and replaced the superdrive with a Matshita that was much better than the Sony Optiarc that was in there. All went without a hitch, but the drive spins up at the beginning of startup, then lays there, refusing to power up/take in a disk. This is precisely what the old superdrive was doing. So, I tested the Optiarc original with an ATAPI connector and ATI to USB adapter and it works JUST FINE. So, I'm thinking logic board, but that seems like an odd thing for the logic board to do. Could it be the PMU malfunctioning and not giving power to the drive after initial power up? System profiler sees NOTHING with both old and new drives. ANY help/experience would be appreciated, folks.
Sincerely,
Jeff

Answer 1

You've narrowed the issue to the highly integrated South Bridge I/O device and disk controller, or to it's path to the internal optical drive connector. The presence of disc spin and lack of logical recognition by the System Profiler application suggests that this is a logical issue with the drive controller itself, and not one involving power. There is likely no evidence of damage to the logic board at all.
In such cases, replacement of the logic board is in order. Out of warranty exchange of such logic boards is a relatively expensive proposition, though the exchange is about 60% of the cost of an outright purchase of such a module.