iMac Intel 21.5" EMC 2308 CPU Replacement

In order for the logic board to come out cleanly, one should remove the RAM at the end of this step.

Definitely! The author should make this as a step in the description (because not everyone reads Comments)

Just did this procedure and the RAM must absolutely come out for the logic board to come free later.

Very easy to lift the glass out. Don't jerk too hard.

I did not have to remove a single cable! After undoing the torx screws from the sides, I was able to rotate the LCD out of the way enough to reach all the screws holding in the ODD bracket. One of them was a bit challenging to get to, but I never felt that I was risking the cables by leaving them connected. Also, it wasn't totally clear, but you have to actually remove the ODD itself from the ODD bracket - 4 torx screws. The SDD mounts into the hard drive enclosure, then the enclosure is screwed into the bracket. Those holes (enclosure <-> Bracket) did not line up correctly for me, and I had to go with only three of them connected in the end. Seems to work fine.

Another comment on DATA & LCD Temp. Sensor cables: I had to remove the vertical sync, and the backlight cable, however, if you have an assistant or/can carefully rotate the screen clockwise/and then have it held up about 5" to 6" at a slight angle, you do not need to remove LCD data cable or LCD thermal cable, however - IMPORTANT: you must have a second pair of hands/or way to securely prop up the LCD. Also, don't rotate too much, since then you will pull out LCD data cable, and it renders the whole exercise moot, or can damage the cable or connector.

Hello, I just need to replace a slightly cracked screen on my iMac. Where is it best to place the suction cups? Thanks in advance

No need for suction cups, I just stuck my nails (short like guys usually have) between the top part of the screen and body, and it came off easily. I've never done it before, so it seems to be very easy.

Nails worked for me too

Just completed the replacement of the optical drive with an SSD using an OWC Data Doubler kit. Attempted to remove the optical drive without disconnecting any cables but found it a bit fiddly to orient the screen for good access. I bit the bullet and disconnected them and found the process less daunting than I imagined. Reconnecting them was similarly straightforward if you're careful.

Tip: you can skip the step for removing the optical drive thermal sensor connector from the motherboard. Still need to remove the sensor from the optical drive but you can leave that hanging and reattach it to the SSD later.

I have an odd question -- I want to remove the polarizer from the LCD. With some monitors this is trivial, others not so much. My question is whether it is bonded to the Liquid crystal, or whether it's loose, or cutting it with a razor blade would remove it. Obviously I'd like to know before I go to the trouble of dismantling the thing... Thanks. Paul

I use Garmin GPS suction cup. Work very well

I’ve just successfully installed a 1TB SSD in place of my optical drive thanks to the information here- thank you to everyone who has contributed!

3 comments- the procedure described here seems to vary between HD replacement and dual HD/optical drive replacement. This can be confusing at times.

Expect there to be minor differences between the layout described and what you find when you open up your iMac. There are also, surprisingly, differences between the HD enclosure description, and the article provided by ifixit.

I was able to replace the DVD/HD enclosure single-handedly without fully removing the LCD, or deconnecting any of the cables (steps 5-11). It’s a bit cramped, and fiddly, but I was not happy removing any of the cables despite watching videos, etc., since they all seemed to involve applying more force than I was comfortable with. A more detailed description of how to release them might have helped, but even here, there may be minor variations even within the 2389 model.

Good luck!

8 vis, pas 2

On reassembly, it is REALLY HARD to align those screws, because of the field of the strong magnets that hold the glass cover on. I'm sure there's a trick to it, but I'd love to know what it is for future reference.

I used needlenose pliers and the T10 to align the screw into the hole. Otherwise the screw keeps jumping to the magnet. And patience with this NON-CAPTIVE screw design (c’mon Apple, even **I** came up with that, and I’m an idiot!)

A short piece of small gauge vinyl tubing that fits tightly over the head of the T-10 driver leaving an 8th of an inch or so in which to insert the screw to engage the head will hold the screw long enough to keep it away from the magnet and get it going in the hole.

When putting the display back I have resistance from the foam elements (on the top end where the iSight is) and have to press down really hard. Is that okay?

Well, stupid me put the 3.5" to 2.5" cage the wrong side up. ;)

Standing the imac upright on its stand really helps this step! Laying it falt makes getting under the panel a real hassle.

The vertical sync cable was snug initially and now is loose. I checked and the cable is intact. Has anyone had experience with making it fit better?

Scotch tape on the upper side and sliding this in helped to secure the cable.

Reassembly of this part was the closest I came to disaster on this project. I tried inserting the connector a few times without success, and when I looked it it the leads, which are fragile, were all mangled. I smoothed them out by hand as best I could and and reinserted, very carefully this time. The trick is that the tip of the connector should be pointed somewhat upwards when reconnecting.

I was pretty sure that when I was done, I would reboot but have no display; but fortunately, everything worked.

Hi, I still have a question. What is the "Job" of the vertical sync ribbon cable. Thanks

So let’s say someone wanted to suck some of the dust off the back of the display before reassembly. Let’s just say that. Someone would likely suck this forsaken cable up into the vacuum tube then, wouldn’t they? They might. And if it were to oscillate in a rushing torrent of air, it might get munged? It might.

Here’s how you overcome such a disaster:

1) cut the end fresh, as close to the end as you can while cutting off any frayed end.

2) abrade the end gently, repeatedly, along the connector wire axis. I used emory paper. Your goal is to expose the copper conductors in the last 1/4” of the fragile evil wire.

3) Tape a small stiff cardstock to the back of the end of the connector. This is essential to press the connector wires into the connector.

4) Gently insert, taking special caution to not peel the copper off of the connector.

5) Tape that connector down deftly, without letting it move a millimeter and securing it for all time.

I just leave it connected. After disconnecting the other cables, there is enough slack to lay the display on its backside if you’re working on a flat surface.

I have replaced the hdd in this model about 8-10 times - I have never had to disconnect any cables other than the sata and temp sensor cables on the hdd. I just prop the lcd up with an egg carton (or something about 3 inches high that is soft and light) and access the hdd that way. The only thing I ever have trouble with are is putting the LCD screws back in around the magnets - but I have pretty much perfected that with a sissor/ tweezer tool.

I found it easier to very slightly lift the front edge of the black connector with a small spudger, then gently pulling away towards the bottom of the iMac. Pressing felt a little crude and didn’t work for me.

in Step 7, my connector (new 21.5 iMac - Dec 2010) was not attached that way and just came of easily.

Aperte as duas exibição do conector do cabo de dados braços juntos para desbloqueá-lo de seu soquete na placa lógica.

I accidently broke the data cable socket on step 7. Any advice on what i should do?

I feel pretty silly. I spent wayyyy too long trying to get these cables disconnected. Happy I found this guide; hopefully, I won't struggle with such simple things since you provide pretty good details! Thanks.

Pas beaucoup de place pour déconnecter ce cable ! En essayant d'ouvrir trop l'écran pour passer mes "grosses mains" j'ai cossé le connecteur : je suis dans le caca :-( (et pourtant j'en fait des démontages !) Alors ATTENTION !!!

This is important regarding the fan running full speed

http://blog.macsales.com/19617-diagnosin...

Is there a way to test the power supply to see if it's dead?

Achtung! Dieser Stecker kann sehr fest sitzen, hier hilft ein guter Fingernagel um den Stecker abwechselnd rechts und links zu Hebeln

Watch orientation of iMac in relation to this picture: if the base is AWAY from you, the screw positions are reversed in this picture. Also use the black power cable for position reference.

I found my DC-In cable VERY difficult to detach. I depressed the locking mechanism, but still needed to use my iFixit Jimmy to carefully, gently, slowly work the cable connector (male) loose and away from the power supply (female).

This was not easy to disconnect with one hand holding the power supply (being careful while holding just to be cautious against any possible electrical discharge). Note that the connector is not on power supply side but on AC-In cable side. Couldn't quite see well enough from photo shown, but hold on the AC-In side of cable connector (depressing the locking mechanism of the male side) and pull away from the Power Supply (female side) cable.

Use a RED marker to tag the RIGHT speaker cable since both speaker cables look identical

Use your fingernails to wiggle out the black tabs at the connector; DON'T use the cable itself to remove from the logic board

These photos do not show this iMac's optional configuration that contains a discreet GPU. If a GPU card is present there is another Torx screw that must be removed that holds an additional heat sink to the upper right corner of the enclosure. Note that in this configuration, the optical drive fan has a different configuration with a plastic separator that points towards the top of the iMac. This looks to serve as channel for airflow and is noteworthy because it makes the optical drive's SATA connector much more difficult to remove and quite difficult (for me anyway) to reassemble as it is a very tight fit!

I made it to this step, then carefully removed dust from the back part, not touching any components, then used compressed air to get dust out since getting the whole logic board was a challenge, assembled and when I turn it on it loads normally, white screen with the logo, but then the screen goes black, and then the fans start running at the actual speed (I used SMC fan control) I had before I unplugged it to clean it, what could have happened? thank you =(

I had the additional GPU card, as mentioned by kevmacmills above, and needed to remove two Torx screws, one short one at the plastic separator, and one 7mm approx at the heatsink in the top right of the enclosure.

OMG!

I cannot believe it!

Only by attaching one side of the golden GPU sionk with aluminum tape on the case, is it possible to well handle the thermal dissipation from the GPU

Was anyone able to install the Q9550S cpu?

Be sure you have REMOVED YOUR RAM MEMORY before trying to wiggle out the logic board!

If you're having trouble getting the logic board to come free, you probably need to remove the RAM. That was keeping it from coming free in my case.