iMac Retina 5K, 27-inch, 2017 won't boot after RAM upgrade to 64GB
Currently my iMac Retina 5K, 27-inch, 2017 has 4 x 8GB DDR4 (2400MHZ) OEM RAM installed.
I wanted to max out the RAM to the full 64GB allowed for my model, so I purchased 4 x 16GB DDR4 RAM (2400MHz) to replace the OEM RAM from the following link on Amazon.
https://www.amazon.co.uk/gp/product/B07Y...
But when I replace the OEM RAM with the 4 newly purchased RAM, my iMac won’t boot up (no Apple logo or chime sound) just stuck on a black screen when the power button is pressed. I've left it in this state for a few minutes as I understand it takes 30secs or so for the iMac to recognise the new RAM, but still nothing.
If I remove all the OEM RAM and install 1 of the newly purchased RAM sticks on its own, the machine boots up. I’ve tested all 4 of the new RAM sticks individually and all 4 boot up the machine and are recognised.
I can then add a 2nd and 3rd newly purchased RAM stick and the iMac still boots up. But once I add the 4th new RAM stick the iMac fails to boot and remains on a black screen.
If I then remove the 4th stick and put back 1 of the OEM sticks along side the 3 other newly purchased sticks the iMac boots up.
Is there a reason I can’t get my machine to power up using all 4 newly purchased RAM sticks? Or is there something I’m missing and need to do? Any help or suggestions would be welcome. Its as if any combination will work as long as its not trying to use the full 64GB size.
Combinations I have tried are:
1-New 16GB (Tried with all 4 sticks)
2-Empty
3-Empty
4-Empty
iMac Boots up
1-Empty
2-New 16GB
3-Empty
4-New 16GB
iMac Boots up
1-New 16GB
2-New 16GB
3-New 16GB
4-Empty
iMac Boots up
1-New 16GB
2-New 16GB
3-New 16GB
4-New 16GB
iMac FAILS to Boot up
1-New 16GB
2-New 16GB
3- Old 8GB
4- New 16GB
iMac Boots up
Esta é uma boa pergunta?
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Two questions:
- What is your macOS version
- Did you speak with the seller? OWC also faced a similar issue which I think involved both the SO-DIMMs and the systems firmware.
por Dan
Hi
- What is your macOS version - Currently running macOS Monterey version 12.6
- Did you speak with the seller? OWC also faced a similar issue which I think involved both the SO-DIMMs and the systems firmware. - Amazon provided replacement sticks which had the same outcome. The sticks work when inserted individually or in pairs or in groups of 3. But fail to work when all 4 are inserted together
por Mr Happy
I ve just encountered the same issue. Was planning to try the same things. If I discover anything new I'll post it.
por Denis
Success!! I thought I had this problem. I wasted some time in clumsy attemptsto insert the sticks, last night, (lifting and laying down computer like a gym workout). Sound was on mute so I couldn't hear the startup signal. ...doh!
Tried again tonight (OWC sticks).
First I tried one stick in slot 1. Success! Then I added another OWC stick in slot 3. Success!! Then another OWC stick in slot 2. Success again!!! Then I put the fourth OWC stick in slot 4. FAIL!! ... I was about to put an original stick in slot 4, but something in my brain said "that slot is tricky, try again!". Removed fourth stick again, Slid it in again very carefully. ... thought I noticed a slight difference in how it came to rest.
BINGO!! All four sticks working together!! Gone for 2x4 = 8 to 4x16 = 64.
Moral? Those very awkward to get to slots seem simple but they are perhaps a little more sensitive than one might have thought. Somehow I found a slightly better alignment for the fourth stick, and the problem was resolved.
Denis
por Denis
Same problem here but I have been trying to make all the gymnastics with this RAM holder but it insists to refuse a boot with all 4 slots installed.
por Greg Pap