(cont.) and it’s where a detailed walk through would be the most helpful. Anyway, if you keep these precautions in mind, you should be able to get through this - but be prepared. And, as a side note, the upgrade from the Core i5 3.4 GHz (4670) to the Core i7 3.5 GHz (4771) didn’t exactly set off fireworks in terms of benchmarks. I saw a 15-20% increase in the Geekbench 5 Multi-Core Score and a nice 30% increase in performance with the Cinebench 20 Score - so, it’s probably going to be worth it in the long run to have upgraded the CPU. If you have a base Core i5 3.2 GHz CPU, you should really see a difference. If you have 3.4 GHz system, you may or may not want to risk going through the upgrade process, as the benefit is much more modest. Your call. I found the biggest bang to be upgrading the 7200 rpm HDD to a PCIe NVMe M.2 SSD drive (I used a Sabrent Rocket Q 1 TB 2280 drive). Personally, I’d do that first and make sure that you have at least 16 GB of memory. You might be happy at this point. Good luck! J
(cont.) chips and hit the power button again. Nada. I started cursing Steve Jobs in his grave. After a couple minutes, it suddenly chimed and in a few seconds the Apple logo appeared and all was well. I’m writing this on my freshly upgraded iMac. What I learned was that as soon as the heat sink touches the CPU, the thermal paste “glues” it to the heat sink - if you twist or hog on the heat sink, the CPU goes with it. The trick is to make sure that the CPU is firmly seated in the socket and then KEEP it there. It takes a good deal of finesse. As “aboucher” pointed out - it is helpful to insert the first screw *just to the point of catching” - then start adding the others in an “X” pattern. Also, I found that removing the “hood” over the adjacent RAM bay (remove the three T5 screws) gives you just a bit more exposure of the CPU and heat sink. I am still amazed that there isn’t a single decent video tutorial that walks you through this step - this is where you’re at the greatest risk of damaging your system..
OK.. I nearly borked my system upgrade at this step. I have a 3.4 GHz Core i5 system and wanted to upgrade the CPU to a Core i7-4771. I found a new one on Amazon last week. Everything went very smoothly until I got to the final “Then, reinstall the heat sink over the top.” step. As others have pointed out - this is really difficult. I had a heck of a time getting the four screws in the tension plate back in. And, after reinstalling everything and hitting the power button, NOTHING happened. Nada. So, I tore the system back down and removed the heat sink. The CPU was stuck fast to the heat sink and it took a lot of twisting and pulling to dislodge it. The CPU looked OK, but when I checked the Haswell socket, I discovered that several of the delicate pins had been bent and were touching. I used a pair of fine pointed tweezers to VERY gently bend the pins back into place. Then, it was “lather, rinse, repeat”.. This time, when I plugged the iMac back in, I got the 3-chime error signal, so I reset the RAM (cont…)
Interesting comments.. personally, I didn’t find the cables particularly difficult to detach and reattach. You do have to be patient and gentle. Personally, I found that a rolled up beach towel gently wedged between the unit and back of the display helped keep the glass up. Also, a small flashlight can be helpful to see the cables and connectors if you’re lighting isn’t perfect.
Umm.. I’m not sure that I’d recommend using a repurposed credit card to open the display - I found that using the “pizza tool” to cut the old adhesive then using a pair of suction cups to gently pull the display up worked perfectly well.
Just completed the Core i5 to i7 CPU upgrade and can strongly recommend getting the “pizza tool” to cut the display adhesive. It worked flawlessly and was done in less than 5 minutes. No inadvertent cables cut. No display problems.
I found that a small pocket knife with a very thin blade worked well to gently pry one corner of the temperature sensor assembly - once that started to come up, I used the plastic spudger to finish prying it up.
While you have the case open this would be a good time to replace the PRAM battery and carefully clean the fan and interior of the case with Q-tips / compressed air.
Used this for my mid-2009 (EMC 2316) 20" iMac - upgraded to a Samsung 500 GB EVO SSD drive. *Just* finished: took about an hour and a half in toto. Just a couple suggestions:
- you'll have the case open: replace the 3V "button" battery while you're in there: it takes 30 seconds and it's done
- have a can of compressed air handy: you can use it to gently clean out the dust, which will have accumulated on the fan blades over time
- I used Carbon Copy Cloner to clone the HD->SSD drive; it worked almost flawlessly: Google Drive needed to be re-synced (easy). Don't forget to deactivate any software that will complain with a change of HD.
- keep in mind that the process is a bit tedious at times: do this when you are rested and have plenty of time; I propped up a laptop with the iFixIt page next to my iMac as I worked on it and this worked well
Lorsqu'il en aura reçu, il pourra afficher un graphique de sa réputation au fil du temps.
Voici un aperçu de ce à quoi ressemble ce graphique :