Replacing Power Supply for 20" iMac w/o the Ambient Light

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Level 1

55 points

Replacing Power Supply for 20" iMac w/o the Ambient Light

I am pretty sure my power supply is dead for the second time. I've taken the back off and done the power button/reset smu test to see if led #2 momentarily blinks, etc. Taking it to the genius bar is a while to see what they say, even though out of warranty.

Anyway, depending on what Apple says at the store about the cost to replace, I may do it myself. It looks like I need part #661-3350 but I am not sure whether it is considered non-PCF or PFC. Does it matter which one I replace it with?

Thanks.

iMac G5 20, iBook G4, iMac alum 24 (OS X 10.5.4), Mac OS X (10.5.6), Linksys WRT54G Firmware v2.04.4, Comcast Cable

Posted on Mar 4, 2009 6:45 AM

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Answer 1

MGW

Level 7

27,041 points

Mar 4, 2009 7:50 AM in response to Twingirlz

Ask the genius when you're there.

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Answer 2

Twingirlz Author

Level 1

55 points

Mar 4, 2009 8:22 AM in response to MGW

Thanks, I did and he said it didn't matter. Just thought I'd check here in case he wouldn't give me an answer. He did say $200 for power supply and $85 for labor. I'm going to DIY. Wish me luck.

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Answer 3

MGW

Level 7

27,041 points

Mar 4, 2009 9:04 AM in response to Twingirlz

Good luck and let us know how you make out.

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Answer 4

Mar 4, 2009 6:54 PM in response to Twingirlz

Hello Twingirlz,

I just removed my power supply and received good guidance from JimWarholic.com. who referred me to this Apple article on PSU replacement:
http://manuals.info.apple.com/en/imacg517inch_PowerSupply.pdf

Here is a suggested source for the 661-3350 power supply:
http://www.dvwarehouse.com/index.php?mainpage=advanced_search_result&search_indescription=1&keyword=661-3350

My G5 1.8 iMac (1st gen)lost it's first power supply at fourteen months. The replacement burnt out recently due to (at least) swollen (defective) capacitors.

So it's somewhat uncertain if your replacement unit will again give up the ghost prematurely. The power supplies I've researched only have a three month guarantee. You can change the PSU without any trouble. But while you have the back cover off, look carefully at the Logic board to check for abnormalities (as in swollen or leaking capacitors (of which there are 25 in plain sight):
http://jimwarholic.com/2008/07/how-to-repair-apple-imac-g5.php

Alex G

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Answer 5

Twingirlz Author

Level 1

55 points

Mar 4, 2009 8:22 PM in response to Alex Gordon

Thanks for the info Alex. I'll definitely use it for my reference. My original power supply died at about 14 months too! So this will be the 2nd time being replaced. The apple tech was a good guy today and he looked inside to make sure the capacitors looked ok and weren't bulging, for me.

What?! I didn't notice the 3 month guarantee on any I looked at, but then again, I didn't really look for a guarantee! If I can get the PSU unplugged then I think I'll be in good shape, that's the part that worries me the most. That it'll be tight and I'll be afraid to pull it apart to hard. We'll see.

Sandy

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Answer 6

Mar 4, 2009 8:43 PM in response to Twingirlz

Sandy,

As long as the "key" or lock tab on the wiring harness joint is pryed up far enough, you'll be able to force the connection apart by inserting the flat blade of a small screwdriver between the two halves and twisting. Work your way around (there is only that one lock tab). The halves will separate grudgingly, but incrementally without undue force.

In fact, start with the twist action until the lock tab is tight. Then pry it up and continue. Worked for me.

Alex G

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Answer 7

Twingirlz Author

Level 1

55 points

Mar 9, 2009 2:47 PM in response to Twingirlz

Whoo Hoo! Can you hear me cheering?!?! I did it and it actually works!!! If I can do it, ANYONE can!

Had a slight issue with the center screw that holds the power supply to the imac frame. I couldn't for the life of me figure out why it wouldn't come loose. (It was at this point that I was starting to get a little nervous!) I think you have to screw it "tight" to actually retract the screw from the power supply. Looked like a clamp type apparatus was there that works to hold the back panel to the frame AND the power supply in place. There was a tiny bolt that was glued to the end of that screw that broke off with all my screwing left and then right trying to figure it out. I don't think that will cause any issues (I hope). I think that was just used as a pressure screw on the power supply as there is no hole for it to actually screw into.

I also think I may have received a used power supply. It had marks in areas that looked like it had been removed from a previous computer. I am going to check applepalace.com's site to see as I didn't notice any information about warranty, as mentioned here. There is a date on the back of the power supplies, the dead one says B0606, I think the new one said B0505.

Thanks for the word of encouragement, it was really so easy!

Sandy

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Answer 8

MGW

Level 7

27,041 points

Mar 9, 2009 3:12 PM in response to Twingirlz

I heard the cheering and I cheer with you, congratulations!!

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