iMac won't boot after ram upgrade

Great - thanks for the feedback!

If you want to upgrade to 32GB of RAM on a late 2013 27" iMac and don't want to pay Apple prices, buy the RAM from OWC.

My iMac, crashed with the first batch of Kingston RAM sourced from an Apple approved service centre. Fortunately I got a full refund then sourced the RAM from OWC and it works perfectly.

The benefits of OWC are

1) You can order and ship globally

2) The price is very competitve

3) The website clearly states how they test the RAM and the comaptibility with your computers model no.

4) They have a 30 day refund and a lifetime replacement policy

5) You can get a rebate on your old RAM, although I didn't bother taking this up.

Having been through the hassle, using OWC RAM is a no brainer and in my opinion the most convenient and effective upgrade. Hope this helps your decision!

I'm sorry for replying in the thread that is almost one year old but I have similar problem - unfortunately it is not identical. 😕

I have a late 2013 iMac with 16GB of memory (2*8GB + 2 empty slots) and I have attempted to upgrade it up to 32GB - the computer is working correctly with old 16GB as well as with new ones but with 32GB on board it does not boot: it starts, then the Apple logo changes into "No entry" sign and nothing happens then.

If the computer is started with "D" key the diagnostic tool reports no problems (reference code ADP000 = no issues).

I have even tried to install brand new 32GB (4 identical modules) and the problem persists: the computer does not boot with 32GB installed. The same situation occurs on OS X Yosemite and OS X Mavericks - nothing has changed after the upgrade, the only difference is the screen color. 🙂

Is there anything else I could try on my own or should I rather send my computer to the service?

Thank you for any suggestions in advance.

You should start your own thread, while your problem is similar it's not the same.

I too have had problems adding ram. I had two 2GB Elpida sticks I added 2 Hynix 2GB - no boot. I waited for a few minutes, you can just about hear the IMAC trying to start but no good.

I tried mixing the slots and sticks in various combinations. I can get 3 to work together (any 3 will do) but with the 4 in no boot. So all the sticks work ok, all the sticks work together but the top two slots, nearest the front can only have one stick in either slot. With the top two slots populated you can not use either of the lower slots.

PITA

Hello,

I installed all 4 same size 4GBx4=16B which, is max for my 21.5" Mid 2011 iMac. All Samsung made in China...?

No chime & boot progress bar is stuck 1/2 way for over 15min???

Please help!

Hello,

All is well. Got a chime right away. Progress bar paused at about 25%. Then, took off like a rocket rest of the way after no more than 30sec.

I took memory out & put it back in with matching 2Rx8 on banks 1&2? (bottom 2 when laying down on screen) & matching 2Rx4 in banks 3&4? (top 2 when laying down on screen). Thought I did matching chip counts the 1st time. Wasn't paying so close attention b/c, it's late, I'm tired & was too excited to wait until tomorrow! Besides, why wait 'til tomorrow for what you can do today, right?! lol 🙂

Here's a screenshot of memory slots/banks:

Now I can say, currently, I have the 21.5" Mid 2011 now with an i3 (slow) & 16GB of RAM (better)! 🙂

Initial desktop load still slower than I would like @ 16GB...? I know that's super lightweight for you 32GB guys. Hopefully, will be faster next time. I'm just hoping to be able to upgrade my iP4s to the new 7 this fall let alone, buy a new iMac. 😉 Would love to have 32GB RAM 1GB video & i7 at least. I'd imagine that's like a TT Supra beast!

Generallly speaking, 3 beeps after ram install means a problem has occurred.

Also, you should be able to take that i3 3.06 out and put an i7 860S or 870S in.

2010 with LGA1156 socket, 73 watts,

i7 860S or 870S, 82 watts....