Re-seating iMac 27 2011 motherboard

[Ron_Harrison]

Hi, I’ve been a spectator of this forum for awhile now, especially of the 2011 iMac GPU upgrade thread. I had acquired one of these machines myself about 4 months ago, I wanted to eventually make it my primary computer, so I set out to install an SSD, additional RAM, along with applying new thermal paste. I just received the custom SATA cable for the SSD today, and everything was going fairly smoothly until I tried to re-insert the motherboard. I usually can figure things out given enough time and concentration, but this has me lost. I’ve tried looking at videos on YT, guides on Ifixit etc. and I just cannot get the motherboard to fit into place. It seems to want to tilt either left or right, letting one side slide in, while causing the other to be too high. The IO ports on the back is where I think the main problem is (can’t get them to align properly with the cut outs no matter what). I’m almost thinking I maybe installed something incorrectly when putting other parts back in?... I really don’t know anymore

Hopefully I don’t sound like a complete fool lol, I would greatly appreciate any recommendations, tips etc. on the best way to go about fitting it back in properly.

If pictures or any further explanation is needed, please just let me know. Thank you

 

[TwoH]

First of all -- make sure all RAM is not currently connected to the logic board, if it is then remove it. Secondly ensure that the left speaker cable has not come out of place and is blocking the logic board from going in correctly.

I prefer to get the right-side of the board in first, quickly followed by the left, and I use fingers if necessary at the RAM hole part to try and push the logic board towards me to give it a little bit of tilt to fit in, after that I will push the CPU heatsink into place. If I don't have enough clearance, I will give it a little whack to try and push it in place.
Before you screw the logic board back in place, make sure you have a few ports plugged around the back (2 USBs and ethernet should do) so that the ports line up correctly with the case

 

[T'hain Esh Kelch]

Yup, not removing the RAM is likely the cause, since it makes the motherboard virtually impossible to get in (I did that mistake just this weekend!).

But use the advice above, and if you can't get it in, it is likely some connector sitting in the way. I usually take all the loose connectors, and tape them to random places, so they get out of the way when I have to put the motherboard back in. Also, get someone to hold the machine up at an angle, as it helps a lot IMHO. The motherboard fits nicely, and you are not in doubt when you have it in place. I never waste time to check if the connectors are sitting correctly, because they always are, when the CPU heatsink is well in place.

 

[mmomega]

Like others mentioned, be at a place to not be rushed, get the board out, RAM out, sometimes the board pushes against the IR sensor in the front chin where the Apple logo is so it may need to be shaken and pushed down gently at the same time.
Once it seats down, I place an ethernet cable in and a USB cable, this helps align both sides of the ports, then tighten down all of the screws with those cables in place.
I will get everything placed back together and standing upright, 1 monitor screw in so the screen does not accidentally tilt forward and fall out, turn the machine on to make sure it boots up properly.
If so, shut down and finish putting it back together.

 

[Brian Y]

Yep, they can be a bugger the first couple of times.

In addition to the above, make sure that your new SATA cable hasn't inadvertently routed itself across one of the screw points.

 

[Juicy Box]

Is the IR sensor removed?

 

[Ron_Harrison]

Thank you everyone for the replies, everyone mentioned something unique, and new to me. I didn’t expect this many people to comment lol, but I’m very thankful. Just as a note, the RAM and IR sensor were indeed already removed, but I still have a lot of new things to try from above.

Thanks again, and I’m about to give it a second shot with the new information in mind, I’m hoping for the best.

 

[Ron_Harrison]

I have good news, it is has successfully been put back in place! More importantly, the machine powers on, and everything seems to be working as it was previously. The SSD is appearing within MacOS as well. Basically everyone’s suggestion came together to make me understand this process quite a bit better lol, taped cables out of the way, made sure none were covering screw stand-offs, CPU heatsink required a little force etc. What seemed to actually seat it into place though, was pulling the motherboard towards the front of the computer with my fingers through the RAM slot door, I heard a small click and it fell into place. So thank you TwoH for recommending that, very relieving moment lol...

Thank you to everyone else who commented as well, I greatly appreciate it.

One last question... when I turned on the computer to test it, I did so without the built-in screen and used an external one instead. About 25 seconds or so after the Apple logo appeared, the CPU and GPU fans ramped up to full blast, but not the HDD one. Everything is connected and all temperatures could be read within MacFanControl. So I’m assuming it’s just because the screen isn’t connected, but before I put it back on, is there anyone who could confirm this? Thank you

 

[TwoH]

Yep, fans are ramping because there is no communication from the LCD temperature sensor, it should work with no issues with the LCD on (unless other sensors have been missed).

 

[Ron_Harrison]

Aha, excellent to hear, and thanks for the quick reply. I guess everything went well then, I had forgotten that there was a temperature for the LCD, so yeah it definitely makes sense lol. Time to put it back on.

 

[Brian Y]

I have good news, it is has successfully been put back in place! More importantly, the machine powers on, and everything seems to be working as it was previously. The SSD is appearing within MacOS as well. Basically everyone’s suggestion came together to make me understand this process quite a bit better lol, taped cables out of the way, made sure none were covering screw stand-offs, CPU heatsink required a little force etc. What seemed to actually seat it into place though, was pulling the motherboard towards the front of the computer with my fingers through the RAM slot door, I heard a small click and it fell into place. So thank you TwoH for recommending that, very relieving moment lol...

Thank you to everyone else who commented as well, I greatly appreciate it.

One last question... when I turned on the computer to test it, I did so without the built-in screen and used an external one instead. About 25 seconds or so after the Apple logo appeared, the CPU and GPU fans ramped up to full blast, but not the HDD one. Everything is connected and all temperatures could be read within MacFanControl. So I’m assuming it’s just because the screen isn’t connected, but before I put it back on, is there anyone who could confirm this? Thank you

As above, that's normal.

Be VERY careful running it like that (and drain it down before putting it back together). You can get a fairly nasty shock from those PSUs - trust me, I know.

 

[Ron_Harrison]

Thank for the word of caution Brian, I’ve been treading with care when working near them, even after having the computer unplugged for awhile. Unfortunately, it looks like I’m not quite done with this thing though... I’m not sure if the quality of the available custom SATA cables differ much, but this one I got off of eBay seems to be faulty, or broke when I tried to unplug it from the board, bending the connectors up slightly. The drive appears (usually, a few times it didn’t or said ‘Unknown’), but I can’t seem to write to it or mount/unmount it after boot up. Disk Utility will eventually report “Failed to write to last block of the device”, but surprisingly Diskpart in Windows was able to wipe it.