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Model A1225 / Mid 2007 and Early 2008 / 2.4, 2.8, or 3.06 GHz Core 2 Duo processor

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Are 661-4665 and 661-4995 PSU's interchangeable?

I have an early 2008 iMac, 3.06 GHz Core 2 Duo (E8435), model A1225 (EMC 2211).

It has 6Gb of ram and a 2TB Western Digital Black hd, along with the Nvidia Geforce 8800GS video card. It has been a great computer.

Over the past 5 years of owning it, the LCD went defective twice, as did the video card, and they were replaced under warranty. But yesterday, the computer made a lovely (and loud) *POP* like a firecracker went off in the system, then died, leaving behind the faint smell of sulfur in the air.

I did my research, popped it open and checked the diagnostic led's, and they were all off, possibly indicating that my 661-4665 PSU was dead.

In trying to find a replacement PSU, I discovered that Apple discontinued the 661-4665 unit (that has 3 heat sinks on it) and replaced it on the next 3.06Ghz iMac with a 661-4995 psu that does not have heat sinks, and is built by Delta instead of the previous LiteOn. The new 661-4995 unit appears to be a little more solidly built, and I was wondering if the 661-4995 will work properly in my system, or should I simply replace it with another 661-4665?

All the connections on them are the same, and the mounting points are identical as near as I can tell.

Just need to know which direction to go!

Thanks very much!


Answered! View the answer I have this problem too

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So, has anyone actually tried replacing the 661-4665 with the 661-4995?


Well... shoot. My new power supply finally arrived. It was only two days late due to the USPS losing it and then trying to deliver it to the WRONG home.

Got the new 661-4665 installed....... and nothing. The iMac is still dead. So at this point I don't know what to do. None of the diagnostic LED's are coming on at all, and I'm flat broke now that I spent my money on a new PSU.

I triple-checked all connections and cables and found... nothing. Something ELSE must have fried along with (or instead of) the power supply. Possibly the logic board?

But since I'm on disability, there's no way I can replace anything else at this point. It's a large, shiny, paper weight, unless someone else has a suggestion I can try.

Thanks all.


Update, October 30th, 2013.

After a lot of digging and searching, it turns out that not only was my PSU fried, but the *new* PSU I ordered from Go Mac Pro on eBay was dead on arrival.

After a bit of chatting with their customer service, they refunded my money, and I took the iMac to a professional Apple trained tech service where they double checked to make sure nothing else was damaged, then they popped in a new power supply for me that they ordered (and TESTED).

So now my iMac is back up and in working order again!


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3 Answers

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Stephen -

Sorry you're having a bad case of luck here. Have you tried leaving the display & HD unplugged as well as pull the memory to see what the diag LED's do? If you get some sign of life you should be able to slowly add things back in to figure out what is shorted out causing the power supply not to power things.

A few questions here:

  • Did you have your computer plugged into a surge protector or UPS?
  • Are you using a cheater plug so you can plug into a two pronged outlet?
  • Have you had an electrician or your self check the ground service of your house and the outlet you are using?
  • Have you had any storms in the area where lighting might have hit near you?

Also, when you take your system apart again make a good visual inspection of the logic board (both sides) Its' possible a capacitor or other component went on you.

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Before reading my post, forgive the formatting of it.

For some reason the line breaks will not work for me and it ends up one gigantic, non-stop post. So, sorry!

Hey Dan! Thanks for replying.

*Computer is plugged into a surge protector....

*No cheater plugs, house is fully wired for proper grounding

*Checked all outlets with a ground meter, they are fine

*Storms yes, lightning no.

I think the computer has just been used so much that something finally gave out. I bought the computer for college almost 6 years ago, and used it for video editing and Photoshop editing. Then ended up using it every day for hours and hours. Probably put more hours on it and more stress on it than was intended.

I found a computer repair shop tonight that offers free diagnostics and they are trained Apple techs. So I will call them tomorrow and see if we can arrange to have it checked.


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Most Helpful Answer

My source ( does not list these as interchangeable.

However lists these part numbers as compatible:

661-4183, 661-4422, 661-4478, 661-4665, 661-4995

I'd go with the best price ;-) Thanks for the email. Glad to try to help!

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Thank you very much for replying! It will take me a few days as I have to sell a camera lens in order to do this, but then I'll mostly likely get the 661-4995, as I found it for $10 less than the other. It's a newer, revised unit, and cheaper... hope that's a good thing *chuckle*.

You know, actually, I just checked the 2nd link that you provided, and it asked for the serial # of my iMac. When I put it in, it said that the 661-4665 would definitely work, but that the 661-4995 may not.

Not sure I want to spend money on something that *may not* work. The 661-4665 worked for 5 years, so I'll just get another one that I know *will* work. :)


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I recently replaced a dead power supply, 661-4665, in Early 2008 iMac 27" with the newer 661-4995 model. Same specs, same shape, same size, etc. Fits perfectly and works perfectly. In service for two months with no issues.

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Stephen will be eternally grateful.
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