iMac bad logic board?

[shouseee]

I recently replaced a couple of point of sale iMacs at our shop with some new Mac Minis. They were both late 2006 17" 2GHz Core 2 Duo models bought as refurbs. I went to erase and restore the two retirees to see if they could still be used at all. One went perfectly and works well for my in-laws, but the other had already shown signs of problems, (i.e. inconsistent random lines/artifacts in screen, kernel panics) and won't hardly boot up now. Other symptoms include the Superdrive not mounting discs at all, and therefore won't run Apple Hardware Test. I have a feeling just cracking the case and blowing out the dust won't help much.

From this can anybody confirm my hunch that the logic board+graphics is likely toast? If I can get one for $50-75 on ebay it might be worth digging in, but even at that I don't know if the part I'm getting will be reliable. Any ideas or opinions, worth it to mess with or staggering on its last leg?

[Xairbusdriver]

I recently experienced some flakey performance on a slightly newer iMac. I would normally suggest having the machine tested at an Apple Store (if one is near) or any shop that deals with Apple products. After my recent experience, I think I'd stay with a non-Apple repair company...it may or may not need a motherboard replacement but you will have a better idea on how much that can cost. I've never been much for eBay as a parts supplier, in that category I think a better name might be "Pig-in-a-Poke!" Others may have better experiences.

Does the Superdrive appear in System Profiler (option-click the Apple menu) or even Disk Utility (probably in your Utilities folder. If it shows in either place, it may just be a dusty laser lens. That can be cleaned a couple of ways; a blast of non-condensing, compressed air or a 'cleaning disk' you can get at many stores.

You might even be able to run the AHT from a mini connected to the iMac with a short piece of Ethernet cable, a simple computer to computer network setup. I think that iMac even has a FireWire port (400?). If so, it can be stated up in Target mode (hold the "T" key down when starting it). But I'm not sure that doing that will help with running AHT.

A further 'aside:' I would encourage you to invest in both Disk Warrior and TechTool Pro. While they both come on disk, they can, of course, be installed on both mini's and run their tests over the network, which I assume you have. Those apps would probably need older versions, however, to test the iMac but I think those versions are available, maybe for free or at reduced prices.

The bottom line, of course, is that the iMac (any of them!) are not designed to be repaired by swapping individual components/circuit boards, it's pretty much everything on one board! Wish I could be more helpful...

[shouseee]

I'm with you on the non-Apple repairs, I won't even get into my last Apple store repair debacle. I like the store, but let's just say there's only room for so many blue shirts in an Apple store, then throw in a throng of customers and pandemonium ensues!

Yes the superdrive shows up in System Profiler...I'll definitely shoot some canned air in the slot. And yes I have yet to try anything with Target disk mode because I keep forgetting my pesky FW400 to FW800 cable at work. My thought was that maybe while the CPU is choking unbearably under snow leopard, that a fresh install of the original 10.4 disk might help it run smooth enough to troubleshoot. Doubtful but maybe?!

I'm pretty sure JWBoyd has Techtool installed on his Macbook Pro. If he's willing I'll see if his version isn't too new to sniff out hardware problems on my old iMac. Even if he's not, I bet I could twist his arm the next time we bring the grandkids to see him. I had no idea you could run tests over a network with it. Thanks for the insight!

[Xairbusdriver]

QUOTE

I had no idea you could run tests over a network with it. Thanks for the insight!

Uhmn...that's more of an "hey, I wonder if that would work?" than an "insight!" But it's easy and cheap to try. My recent Store experience actually did use their 'back-room' server to run the tests, however.

I'll go out on a slim limb and suggest that the Super Drive is at least partially operable since it shows up in SP. But is cleaning doesn't help, it could be almost anything from a burned out laser light bulb (tricky to change and seldom available at Home Depot) to its own controller board. Without knowing more details of what's wrong, it's hard to make suggestions about possible fixes (like a tear down and drive replacement). You might find a good Apple-knowledgable repair shop in Indianapolis, if you don't already know of one.

You should be careful using any Utility on an older machine, assuming it even runs. Hardware testing is one thing, but file testing and especially repairing can do serious harm if the app was not specifically designed for the OS.

BTW, tell the "old man" hello for me when you take those youngin's to see him. Don't you have a pretty new one? less than a year old?

[tacit]

QUOTE(shouseee @ Jul 21 2011, 02:31 AM) <{POST_SNAPBACK}>

I recently replaced a couple of point of sale iMacs at our shop with some new Mac Minis. They were both late 2006 17" 2GHz Core 2 Duo models bought as refurbs. I went to erase and restore the two retirees to see if they could still be used at all. One went perfectly and works well for my in-laws, but the other had already shown signs of problems, (i.e. inconsistent random lines/artifacts in screen, kernel panics) and won't hardly boot up now.

The artifacts on the screen and kernel panics definitely point toward a hardware problem. My hunch is bad video RAM; probably requiring a logic board replacement. So I suspect your instincts are right, and further suspect that replacing the logic board at this point would cost more than the computer is worth.

[jcarter]

Remember my problem?  Many kernal panics, and 4 logic board repairs and power supplies.
I could go back thru the posts and find it if I had time.

It was probably 3 years old, and I think it was 2009 when this happened.
Somebody here sent me a link that showed that there was a group of serial numbers of iMacs which had this problem, and mine was in this group.

My local independent Apple store repaired it 4 times.
On the phone with Applecare,,,,,,this is great, the rep said "If this happens once more to this person, she will be eligable for a new Mac".
It did happen, though the Applecare was out, as it was 4 years old. But after long phone talk with another rep, 2 days later after I had shipped the broken one to them, the new one arrived!
The broken one was a 20 incher, but I was able to talk them into a 24 incher!

Thats why I swear by Applecare, and this one is the one that is my free replacement, still going strong. They didnt even charge me for the shipping.
Jane