Sostituzione scheda grafica iMac Intel 21.5" EMC 2389

Before beginning unplug your iMac.

The screws are not phillips #1 as implied above. My phillips#2 bit fit.

Yes phillips #2 is the correct Bit

Just FYI you can install 32GB’s of RAM in this machine. I have been using it this way for over 2 years now.

Thanks for your Useful guide …. iMac Intel 21.5" EMC 2428 RAM Replacement was performed step by step on my Imac and every thing is perfect right now.

would this be a good time to increase the size of the RAM too? Would it be as simple as slipping the new RAM in when redoing the steps? Thanks

When reinstalling RAM in this machine or any iMac with upgradable RAM slots push hard to get them to go in (Apple really did make this one harder than it needed to be). If you don't push hard it won't go in and your computer won't work. (trust me on this learned the hard way)

Is there an expirience to settle 1600 MgH Ram instead 1333 MgH manual required?

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

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.

Wearing Nitrile or regular surgical gloves helps prevent finger prints if you accidentally touch the glass.

I use a Swiffer duster from above at the last moment before I let the magnets grab the glass cover. This has worked so well the last dozen or so times I’ve replaced a glass cover since I never have access to a “clean room” and don’t wear a “bunny suit”.

Also, more dust will shed from your skin if you’ve just taken a shower, so I like to finish these repairs in the morning before a shower.

Replacing the screws , especially the two uppermost ones , is awkward due to the magnets attracting the screws off the Torx driver

I’ve done an HDD replacement on an A1174 (and I’m about to do this model), which is nightmarish, but by far the best solution I found was to use a bit of Blu Tack or the equivalent on the driver.

After sliding the display slightly towards the top edge, enough for the bottom edge to clear the retainers, an alternative is to raise the bottom edge out. Then unplug the LED backlight power cable (this step + 2), unplug the LCD thermal sensor cable (this step + 4), unplug the display data cable (this step + 3), and the display may be rotated over the top edge while leaving the vertical sync cable attached (this step + 1).

Do not try to pull the plug off the circuit board as it's soldered. Pull the cable sideways out of the socket.

Skipped step 5-10. I used two 5-6" chopsticks to prop up the display, this gave me more than enough room to complete the rest of the steps. I only had to disconnect the 3 cables are directly connected to the hard drive. Replacing the Seagate hard drive with another Seagate hard drive eliminated any cable issues. Now I have 2TB SSDH

I was also able to skip steps 5 thru 10, which meant no messing with any cables except for the two for the HD (steps 13+14). Used a credit card to start the removal of glass panel (step 2) - much easier than I imagined. After removing display screws (step 3) I simply had a friend hold up the display's bottom edge as far as the cables would allow (careful not to stress at connection to logic board) and this provided enough room to remove the HD bracket screws (step 11), detach the HD cables, and remove the HD. Was replacing a failed 1TB Seagate with a 3TB Seagate so no problems with compatibility when reattaching the HD cables and everything worked fine when I restored the OS and data to the new HD. No fan issues. I did take great care to not get fingerprints on the inside of the glass panel and to blow off any dust specks before reinstalling it. It was a bit tricky to get the new HD back in without letting the magnets get a hold of it, so thanks for the warning posted here about that!

This is real tricky it is fragile and you have to pull it along the logic board.

First push down on the edge of the connector closest to bottom edge of the iMac. This unlatches the locking mechanism at the top edge of the connector. Then gently wiggle the connector away from its socket.

This cable is very short, I would remove it before any of the others. First time I did this, I didn't realize this and this cable just popped out of it's socket. Luckily, the board wasn't damaged.

Be very careful - this connector very difficult to disconnect, and you have a high risk of pulling the cable pins out of the connect. If you have disconnected the 3 other cables, you can have a helper rotate the screen out of the way while you remove the hard drive.

I found this connector impossible to remove

I also found this extremely difficult to remove. Tiny cable with a death grip. I tried using two spudgers, my fingernails, and walking it out. In the end, I used two spudgers and pried it up, using leverage from the clip to the right.

Also, i recommend setting the iMac upright for this. I rested the screen on my chest while I dual wielded my spudgers.

The 4 srews are equal

No need to do this! Just gently pull up the felt-pad sticky on top of the thermal sensor (looks like a tiny circuit board), then (again gently) peel the thermal sensor off the ODD. Leave it hanging while you remove the ODD and replace it with the SSD, then just put the thermal sensor covered by the protective felt-pad back onto the SSD enclosure.

I agree with cdansmith1, above.

I had removed the sensor completely. Booted up and the fan was like a jet engine - 4200rpm! I opened up the mac again to check the LCD thermal sensor cable was connected properly (as warned in Step 8). It was.

So, I simply used the spudger to peel off the felt sticky pad from and then the optical drive sensor too from the drive I'd taken out. Stuck the sensor onto the SSD using the same sticky pad, plugged it back into the original socket. Bingo. Booted up and everything was back to normal.

this part is complicated because the wire is very delicate. when you try to extract it passing through the others elements this wire trap it very easily on the other elements of the logic board

This is the one with a large head.

If you need to clean it watch here how to easily open it: '''https://youtu.be/MWHcPpSL4O0'''

Be careful, reinstalling the logic board, some of these cables stand under the card and you have to remove the card again to get them… :((

When replacing it, copper points down.

Be super careful here. I spudged the sockets completely off the airport card when I was pulling apart mine.

I as well. These are delicate connectors...

Don't forget the red one in the top corner!

Make sure the system has been powered off for a while. The capacitors on the power supply can still hold a charge for roughly 15 mins and will electrocute you if not handled properly

No need to do this if you’re just going to pull out the logic board for GPU replacement.

it's possible to change the HDD fan without completely removing either the main board or the power supply. After removing the 4 screws on the PS board, I only had to pull it outward a few mm to remove the plastic wall on the HDD side, which is the part which holds the heat sink (attached to the main board) in place, Once the wires were unplugged from the main board's edges, and the IR board detached from the case front, I was able (with some delicate wiggling) to tilt the board out at the top enough (without unplugging anything from the back side of the board!) to remove the fan. The only tricky bit was getting that one fan screw out, which I managed with a T10 bit fastened to a 1/4" open-end wrench with some masking tape. A little awkward, but it saved a whole lot of disassembly. Somebody probably makes a skinny little ratchet that takes 1/4 hex bits directly, which would have made it easy.

Last step needed. Once board is free and you can see the battery hidden in the back, very easy to remove. Great guide!

Stopped here, once the logic board was free, I could just simply get to the battery

I noticed here that I had forgotten the top screw of step 34

didn't need to do this

Step 44 Instruction is confusing. Why?

Because you suddenly mention a "mini display port cable" and "a USB cable" that up until now have never been mentioned. I'm not trying to be horsey, truly I'm not, but if you mean "plug in THE mini display port cable and THE USB cable" then I can assume both of these have previously been removed, although in scrolling back over all steps before step 44, I see no mention of either. So I remain confused about this instruction. All the rest of the steps are wonderfully clear and amazing. Apple itself cannot have provided a more perfect instruction (nor would they!). Well I'll leave this comment, although in re-reading Instruction 44, I now understand that these two cables are to be plugged in on the FRAME of the iMAC, OUTSIDE, so as to make sure the logic board INSIDE ends up properly aligned when reinstalled. My initial bad. Thank you.

I think this are also 6.5 mm T10 (!) Torx screws.

Yes, T10 for sure.

My replacement card had a clamping bracket with small bushings in the holes which required a smaller screw! Oh fun! I used a T6 screwdriver to carefully and gently push them up from underneath to get the bracket off. It’s lightly glued on, don’t worry about that; you won’t peel off any traces or board. But DO NOT let the card flex when you do this. Then I reused the old bracket and screws. I suppose you could also drill out the bushings. Curtis Gross talks about this in his nice YouTube video.

Make sure you use Thermal pads not paste on the VRAM chips!

Apple did use a gapping thermal paste but experience has shown the pads are better here. They did this to cut down the amount of time during assembly as pads do take a bit more time to put on.

Too late.

This image is very misleading : (

Please make this a warning, tell about the pads in the description and/or use a better picture!

My card is probably gone.

I used K4 and K5 pro with mine. K4 for the gpu and K5 for the RAM chips.

K5 is a lot thicker and works just like thermal pads.