2006 iMac with unknown issue

Question

Level 1

4 points

2006 iMac with unknown issue

Hello everyone,

long story short: I have an iMac from 2006 that I would love to get working again. I thought it was dead, but it suddenly sprung back into life… for about 5 minutes. The computer starts up, but only gets to the desktop once every 6-7 startups or so. The display is damaged. I would like to find out:

a) is it just the screen that is having some sort of issue?

or

b) are there other parts of the system (maybe ram or the motherboard itself) that is causing the issue and if so, how can I pinpoint the issue?

Here's the full backstory:

I recently bought two iMacs (white 24" from 2006) one of them having a broken display and the other showing no sign of life at all but with the display in tact.

I swapped the displays and put both machines back together. That was about six months ago. I had placed the broken on a shelf as decoration. Today, for fun, I decided to plug the broken machine into power and press its power button.

Suddenly the fans speed up and the dead iMac became alive. I connected a mouse and keyboard and was able to use the computer like nothing was wrong with it. I was totally baffled. This also when I decided to check the specs. However, I was cheering with excitement too soon: kernel panic.

Since then I haven't been able to boot the computer properly. It either boots to a blank white screen (not gray because it is brighter than the startup screen with the apple logo) but there is no cursor. Sometimes, it gets to the desktop with the cursor but I can't do anything. I can move the cursor around without a problem but when I klick on something or hover over the dock nothing happens.

One time the I was able to get to the desktop again and launch iTunes but with severe graphic issues. The computer reacts when I change the volume or adjust brightness but the screen remains partially frozen (see picture).

I am wondering if there is something wrong with the OS or something inside the machine is failing. Perhaps a new hard drive or different RAM could fix the issue? Or perhaps the display cable isn't in right? I also don't have the original DVDs for this machine so I wasn't able to run Apple Hardware Test.

I have exhausted all my knowledge on this machine. I hope of you can guide me towards a solution.

Specs of the computer:

iMac 24" White

2.16 GHz Intel Core 2 Duo

4GB 667MHz DDR2 SDRAM

NVIDIA GeForce 7300 GT 128MB

Thanks in advance!

Posted on Mar 29, 2020 6:16 AM

Reply

Answer 1

Mar 30, 2020 6:37 PM in response to Tuskuno

The white 2006 iMacs had a lot of issues. The LCD Panels would fail and the power supply and Logic Boards would have bulging & leaking capacitors. IIRC the capacitors are located on the back side of the Logic Board.

Plus you could have a bad hard drive.

There is so much on the white iMacs that can cause the symptoms you are describing.

Example of bulging & leaking capacitors (photo is from an iMac G5, but you get the idea). The capacitors are the cylindrical components which should have a completely flat top, but you can see some of the are bulging slightly (rounded top) and others also have some brown gunk leaking from the top.

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Answer 2

Tuskuno Author

Level 1

4 points

Apr 3, 2020 12:00 PM in response to BDAqua

You're right on the money!

I had an old SSD floating around so I put it in an enclosure, connected it via USB, installed Lion on it and proceeded to boot from there. The iMac was running a lot smoother already but would shut down after a few minutes. I noticed it would get pretty toasty. Turns out the GPU was overheating. Manually running the fans at max speed solved the issue until I can get my hands on some thermal paste.

So I guess you solved my problem by predicting it? haha

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Answer 3

BDAqua

Level 10

251,131 points

Mar 29, 2020 10:55 AM in response to Tuskuno

Safe Boot from the HD, (holding Shift key down at startup), does the problem occur in Safe Mode?

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Answer 4

Tuskuno Author

Level 1

4 points

Mar 30, 2020 4:33 AM in response to BDAqua

yes I did but that just produced the same result only slower. I also tried verbose mode by pressing command+v. I'm not the biggest terminal expert but I could see there were a few issues listed concerning the BIOS.

I took the entire machine apart, cleaned everything and it worked beautifully for 5 hours until it ran into a kernel panic.

I went on reddit last night and found this github page where you can use terminal to download AHT images from Apple. I managed to run both the regular and extended tests. Result: NO ERROR FOUND! 😂

since I booted the AHT from a USB stick and everything was fine I was thinking the hard drive might be failing. so I guess my next attempt will be to install Lion onto a bootable USB and boot from there. if that fixes it a new ssd should solve the issue.

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Answer 5

John Galt

Level 10

158,298 points

Mar 30, 2020 5:05 AM in response to Tuskuno

AHT is only available on the original, grey, "Applications Install DVD" that should accompany every Mac that included them when they were originally sold.

No matter though since AHT's only outcomes that matter are "no trouble found" when trouble clearly exists, or to definitely identify a problem that only Apple can fix anyway... and Apple no longer services Macs that old.

What you need to do with that Snow Leopard DVD is to erase the Mac completely and install Snow Leopard. Then you're working from a known starting point.

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Answer 6

John Galt

Level 10

158,298 points

Mar 29, 2020 9:06 AM in response to Tuskuno

What if anything do you have in the way of macOS installation media? Lacking its original DVDs you will need to obtain something to even begin troubleshooting.

Hardware doesn't last forever. Macs manufactured prior to RoHS lasted longer than those after, but that applies to electronic equipment in general. Anything can be fixed, but given that one's age it's economically unjustified to even try. A retail Snow Leopard installation DVD (which Apple no longer sells, and you would need to obtain) isn't worth the cost in my opinion.

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Answer 7

Tuskuno Author

Level 1

4 points

Mar 30, 2020 4:36 AM in response to dialabrain

Dude, do you have any idea how sexy these iMacs are? I love them. They're childhood to me. I love them because they only run Lion. Everything is so beautifully skeuomorphic. Plus I can run all my PowerPC applications again since my PowerMac G4 suffered a power supply failure and toasted the motherboard.

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