iMac 5k 2015 won't power at all after NVME upgrade

[quartzite]

Hi All,

I just replaced the NVME in my iMac, but now when I turn it on absolutely nothing seems to happen. No fan noise, no hdd noise, etc.

I don't think I broke the power button, but I tried connecting the pins in the power button connector together to see if that helped. No dice.

Any idea what I could try next? I checked all the connections on the power board and they seem fine... I've done a few Mac repairs before and I felt this one went well so I'm kinda surprised.

I'm currently testing it with the display unhooked, but I did try once with the display plugged in.

Edit: I can hear some "whine" from the power board with the power supply plugged in, but pressing/holding the power button doesn't seem to change the sound at all

 

[PaulD-UK]

Are any of the four 'status' LEDs on the bottom left corner of the logic board lit up?

 

[quartzite]

Are any of the four 'status' LEDs on the bottom left corner of the logic board lit up?

Thanks for this, I was failing to find this article. None of the LEDs are lit. I wonder if I forgot to hook up a cable or something.

 

[quartzite]

I'm pretty sure I fried something. It was given to me to free, my backup plan was to turn it into a monitor anyways

 

[PaulD-UK]

The PSU when connected to mains power is fully powered on whether or not the iMac's power button is pressed, so the power status lights should be lit if your PSU is making noises.

The power button on/off line seems to be passed straight through the PSU to the logic board through the 7 pin connection flat cable between PSU and logic board, and the logic board passes back the on/off command back to the PSU to put it into standby mode.

So the connector cable between the PSU and logic board is the first thing to check that it is properly connected.

It will make a great monitor if the screen panel is good.

 

[quartzite]

The PSU when connected to mains power is fully powered on whether or not the iMac's power button is pressed, so the power status lights should be lit if your PSU is making noises.

The power button on/off line seems to be passed straight through the PSU to the logic board through the 7 pin connection flat cable between PSU and logic board, and the logic board passes back the on/off command back to the PSU to put it into standby mode.

So the connector between the PSU and logic board is the first thing to check that it is properly connected.

It will make a great monitor if the screen panel is good.

Thanks for the reply! I tried reseating the 7-pin connector, still not getting any of the status lights. Do you know if the status lights would light even if something on the mobo got zapped?

The panel looks excellent luckily 😂

 

[Significant1]

Don't you still need an adapter. I know I had to use an adapter in my 2013 MacBook air.

Upgrading 2013-2015 Macbook Pro SSD to M.2 NVMe

This thread is about upgrading MacBook Airs & Macbook Pros (2013-2015) with new high speed and/or high capacity NVMe SSDs. This thread was one of the first to talk about MacBook Pro NVMe SSD upgrades on Macrumors, and was started by user "maxthackray", which we can thank and give tribute for...

forums.macrumors.com

 

[quartzite]

Don't you still need an adapter. I know I had to use an adapter in my 2013 MacBook air.

For the NVME? Yes, I used one of these: https://www.amazon.com/dp/B01CWWAENG

 

[PaulD-UK]

I would guess that the low voltage output side of the PSU has failed, perhaps a mosfet - maybe caused by a mobo short.
It's quite a noisy PSU, so any noise you are hearing is possibly from the high voltage input circuits or transformer.
But that's a complete guess.

All the other connections to the logic board are peripherals, so the diagnostics LEDs should work normally if there is a connection problem - unless a dead short has damaged the PSU...

 

[quartzite]

I tried removing the new nvme+adapter and added the old apple one. Now I get LEDs! testing more

 

[quartzite]

Well I tried reseating the adapter+nvme multiple times, and the issue remains. There is no problem with just the adapter. But I'd be surprised if the NVME is actually the problem.

I think I'm just going to get an OWC drive instead, even though they are overpriced and the computer will have less storage. I might also order another adapter to test that too as the OWC won't be in until Thursday.

 

[Jumpthesnark]

Well I tried reseating the adapter+nvme multiple times, and the issue remains. There is no problem with just the adapter. But I'd be surprised if the NVME is actually the problem.

I think I'm just going to get an OWC drive instead, even though they are overpriced and the computer will have less storage. I might also order another adapter to test that too as the OWC won't be in until Thursday.

Any way to test the NVME on a different adapter & computer?

 

[Nguyen Duc Hieu]

Well I tried reseating the adapter+nvme multiple times, and the issue remains. There is no problem with just the adapter. But I'd be surprised if the NVME is actually the problem.

I think I'm just going to get an OWC drive instead, even though they are overpriced and the computer will have less storage. I might also order another adapter to test that too as the OWC won't be in until Thursday.

If the iMac runs normally when you put the stock nVME back in, then I think you can conclude that the nVME adapter or the combo of nVME +adapter caused the short. What a relief!

 

[iMac2019]

Maybe you should have a look here :

Many of the available Blade Adapters have their connecter PINS exposed such that when inserted into the Logic board, they short out on the shield of the socket on the Logic board.
So it's highly recommended to cover these pins with Kapton tape.
See examples of what other users have done here and here

 

[Fishrrman]

OP wrote:
"I think I'm just going to get an OWC drive instead, even though they are overpriced and the computer will have less storage"

There's an old saying for doing things like this.
It's called "throwing away good money after bad..."

 

[quartzite]

Maybe you should have a look here :

Many of the available Blade Adapters have their connecter PINS exposed such that when inserted into the Logic board, they short out on the shield of the socket on the Logic board.
So it's highly recommended to cover these pins with Kapton tape.
See examples of what other users have done here and here

Oh good call! I had seen people using Kapton tape but I hadn't seen this was where things were shorting.

I ended up just buying a used OWC Drive off eBay for a really good price, so I'm going to return the adapter/NVME to Amazon as that's easy and seems a bit less sketchy to being bumped etc.

Waiting a bit lets me procure the correct BR 2032 battery instead of a CR, which is good for the longevity of the machine.

Thanks for the advice everyone

 

[ignatius345]

I tried removing the new nvme+adapter and added the old apple one. Now I get LEDs! testing more

You might want to take a look through here. Lots of very specific info on which adapters to use, etc.

A list of successful iMac 27" (2012-2019) SSD upgrades

Here you can find and discuss all the collected knowledge regarding upgrading the HDD, blade SSD and CPU of a 27" iMac 2012-2019, as well as a list of performed upgrades. Here is a list of all 27" iMac models subjected in this thread: Late 2012 - 13.2 - MD095LL/A (2.9Ghz i5-3470S, HDD only /...

forums.macrumors.com

 

[iMac2019]

Oh good call! I had seen people using Kapton tape but I hadn't seen this was where things were shorting.

I ended up just buying a used OWC Drive off eBay for a really good price, so I'm going to return the adapter/NVME to Amazon as that's easy and seems a bit less sketchy to being bumped etc.

Waiting a bit lets me procure the correct BR 2032 battery instead of a CR, which is good for the longevity of the machine.

Thanks for the advice everyone

Very good advice to also change the battery on the motherboard when taking the surgery route.
Unfortunately, I forgot to replace it.
Considering the ever-present risk of breaking something when opening the machine, I'd like to avoid doing it as much as possible as long as the machine is running smoothly.
If it's not broken, don't fix it.
Keep us informed on your hw upgrade

 

[quartzite]

The OWC NVMe I bought off eBay arrived today. Computer was able to boot with it, turns out nothing else was wrong .

I glued it back together and am now installing an OS. Thanks everyone for the help and advice, my partner is looking forward to using the machine with its gorgeous display.