@fex42 Thanks! I'll see if there's a way to incorporate your fix into the guide as an alternate path to follow.

Hi @goaty , can you comment on the suggestion from @fex42 about using an MP1584EN chip? On paper, it looks to be a better chip with higher max ratings (3 vs 2 A, 1.5 vs 1 MHz, 28 vs 20 V). fex42 also said piggybacking the chip was simpler than removing the old one, but they were vague about how it got wired up. I cannot find the MXT2410SX datasheet so I do not know if this is supposed to be a pin-compatible replacement.

On Dec 8, 2024 @fex42 wrote:

Instead of repairing the defective 5V control circuit, I simply piggybacked a small switching regulator on top with thick double-sided tape. By removing the coil, the output of the defective original regulator is separated from the rest of the circuit and you have a nice contact on the board to feed in the 5V. This is not only much easier than replacing the chip (which I also have done successfully some years ago) but these small DC-DC buck converters with MP1584EN chip are simpler to source than the original MXT2410SX chip and also cheap.

Nice idea, fex42! Did you take photos of the process? It would be good to update the guide with your simpler piggyback method.

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I can't find the datasheet for the original MXT2410SX chip, so I'm not even sure what "pin compatible" looks like or why removing the coil disconnects the defective chip. Can you explain a little more?

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It looks like Monolithic will be discontinuing the MP1584EN. Would the MP2410GJE or MP2338 work? I notice that the 1584 seems to have much better specs (higher current, voltage, and switching speed), but it'd be good to give people options if it starts becoming hard to find.

(Update: I believe Apple's wording was incorrect. "Top" is closest to the stand, not the display, because those are the slots which had the SO-DIMMs in the iMac I just checked.)

It does make a difference, but only if you have a single stick of memory. Here's what Apple says about the 27" 2011 iMac:

"i5 and i7 Quad Core iMac computers come with both top memory slots populated. These computers will not start up if only a single DIMM is installed in any bottom slot; these computers should operate normally with a single DIMM installed in any top slot.

Core Duo iMac computers should operate normally with a single DIMM installed in any slot, top or bottom. ("Top" and "bottom" slots refer to the orientation of the slots in the pictures below. "Top" refers to the slots closest to the display; "bottom" refers to the slots closest to the stand.)"

Source: https://support.apple.com/en-us/108317#2

Amusingly, although Apple defines "bottom" as being closer to the stand, that is opposite to the orientation of the pictures.

Apple does not mention memory channels in their text or diagrams. Since they came with both top slots populated, a good bet is that they are on separate channels (left and right).

Nice tip, Clinton! I’ll have to try that next time. Do you have photos of how it is done so this guide can be updated?

Two screws need to be removed. Before lifting, slide the base cover slightly towards the battery to release it.

P.s. this isn't as important, but where did you hear the tip about the hairdryer? I'd leave that out as firmly peeling it up works fine.

Thanks for incorporating some of my edits and for taking new photos.

Are you the one who took the original photographs? If so, you did originally have the hard plastic retainer as it was in those photos, just obscured by your thumbnail. The glue on the retainer allows it to shift a bit, so it's possible you took out the cable and knocked off the retainer without noticing it.

Your two frame animation of pulling out the plug is helpful to show the proper direction. Given the number of people who have destroyed their MacBooks from this procedure, I think we should do even better. The instruction would be clearer if it said, “Disconnect the camera cable by sliding it horizontally out of its socket.”

Also, if you can post a link to a picture without fingers in the shot, I will add an arrow showing the proper direction. (I would have added it to the original, but visually it would have gone through your fingers.)

This step is unnecessarily tricky. I’ve tried to make it better by adding images highlighting the plastic stopper thingy and showing a clear arrow of the direction the cable should be pulled.

However, simply pulling the cable may not be enough to remove it. It sure wasn’t for me. I think there ought to be a close-up of the two little nubbins on the sides of the plug which one uses to wiggle it loose from the connector by gently prying with a tiny flathead screwdriver. I didn’t add that tip because (a) it would have made the instructions longer, (b) I didn’t think to take a photo of it, and (c) using a screwdriver carelessly next to the logic board could scratch or break components on the motherboard. A guitar pick or very small spudger might work.