burkphoto Loc: High Point, NC

Macs can use several different drive format schemes:

MacOS Extended, Journaled (older)
ExFAT (for Windows compatibility)
APFS (Apple’s newest, fastest scheme, meant for SSD drives and pure hard drives — NOT hybrid drives.)

So: If the drive does not read on Windows, try another Mac...

I still suspect that this instance is a chip failure on the motherboard. Power surges can kill one of the microchips that affects both USB ports.

GrandmaG Loc: Flat Rock, MI

Are you saying this because the MAC can’t see the files? When I had this problem, Apple Support did not suggest this to me. I just stopped using the drive the iMAC couldn’t see. I would love to find a fix for this problem as I’m sure the OP would too.

therwol Loc: USA

Again, where is the OP? Many suggestions have been made and questions asked.

burkphoto Loc: High Point, NC

There are many things that can occur in the course of not seeing your files.

If the drive mounts on the desktop, or appears in a Finder sidebar, then I would suspect directory corruption and run Disk First Aid from the Disk Utility. If that comes out normal, but you still can't see files, then your drive needs professional assistance.

If the drive never mounts when you plug it in, suspect the drive, the USB port, or the cable.

If the drive spins, but sits there clicking, it has had a hardware failure and it needs professional assistance to recover your files.

If NOTHING works in that USB port (i.e.; phone won't charge, flash drives don't mount, etc.), then it is not the cable or the drive. It could be a chip that controls that port, or a chip that controls both ports. It could be both of those chips. It could be that the USB connector has become disconnected from the motherboard (main circuit board in the computer) due to mishandling, a drop, etc.

If ONE of the USB ports works and the other doesn't, then the problem is likely due to one chip that drives that port, or a connector failure as described above.

Of course, there are other possibilities... including operating system corruption. When was the last time you backed everything up to a Time Machine drive and totally rebuilt your startup drive? Most Mac users never do that, but it cures a multitude of ills. It takes two or three days, but it is less costly than buying a new computer.

Last December, I put a new 2TB SSD drive and 16 GB RAM in my 5-year-old iMac, with parts and a video from OWC. I installed a virgin copy of MacOS 10.14.4 and re-downloaded all my applications from Adobe, Microsoft, the App Store, and some independent vendors. I re-licensed/re-activated everything, using my various accounts and serial numbers. Then, I migrated just my data back to the iMac from the old drive. The result is that I have a Mac that flies, compared to what it did before. Everything is much faster except processor-intensive tasks, which are mostly fast enough.

I back up everything to Time Machine weekly, or after any significant file creation or download. I have a pair of drives that I rotate out for this backup.

GrandmaG Loc: Flat Rock, MI

Thank you for the answer. The drive in question did mount and it did not disappear from FINDER, just the files disappeared. There were actually still on the drive but iMAC wasn’t showing them. I had to restart the computer to get them back. I tried other ports, no difference.

I called Apple Support and they had me reinstall the OS. Still didn’t fix it.

I did go to disk utility and when the files were missing, it failed. I sent a screenshot to WD and they replaced the drive; but the new drive did the same thing. I gave the drive professional help...right in the trash can!!

As far as backups, I’ve used Time Machine since I’ve had the iMAC but I’ve never rebuilt my startup drive. My personal data is double backed up to a G-Tech NAS system up to 2018 for pictures. It’s starting to get a little full, so I’m using a CRU Tough Tech Duo to double backup pictures from 2015 to current (I will eventually take 2015-2018 pictures off the G-Tech because they are on the CRU). I have a third drive that I swap out monthly, which is kept in the safe. My Lightroom Catalog is on a small Seagate drive along with the current years pictures. I also have Carbonite, but I’m thinking about switching to Backblaze.

I would be a little afraid to start all over like you did. I’ve done that sort of thing before and it seems there’s always something that I missed. Plus, it is very time-consuming as you said. Did you upgrade the iMac yourself? There’s no access on mine to do that. Your startup drive is your new SSD? Mine has a 1.12 TB Fusion drive that is less than half full and 32GB of RAM.

burkphoto Loc: High Point, NC

Wow! Okay, it seems you've exhausted all the obvious troubleshooting options. I don't really have any more suggestions. I do stay away from the less expensive Western Digital drives. They make Enterprise Class drives that are quite reliable, however.

I have a Late 2013, 21.5" iMac. It came with 8GB of RAM and a 1TB conventional 5400 RPM hard drive. Apple, of course, sealed the case and said, "It's not upgradeable." Well, it is, IF you are a brave soul and truly do know how to use tiny tools. My particular model has SOCKETED RAM. Some don't. I would not have bought it if I didn't know that in advance.

Other World Computing at https://www.macsales.com and iFixIt at https://www.ifixit.com both have parts to upgrade and repair Macs, and they also have step-by-step guides. OWC uses excellent HD videos, while iFixIt uses Dozuki "partly crowd sourced" repair manuals with great close-up photos. Either will guide you well. I read the manual and watched the video twice before I ever ordered the parts.

I bought two 8GB RAM modules and a 2TB SSD from OWC. They came with a kit of tools and the double-sided foam tape that holds the perimeter of the screen onto the case. The tools include all the tiny screwdrivers, a "pizza wheel"-like cutter for the foam tape, and two suction cups that mount on the glass screen and allow you to lift it off after cutting all the tape with the pizza wheel cutter.

I had the OWC video running on my iPhone next to me. I would start it, watch the next step, then perform that step. All small parts like screws went into individual wells of a muffin tin as I worked along. I worked on a static free mat and wore a grounded wrist strap I've had since I upgraded my first Mac SE in 1989. The entire process of opening the Mac, replacing the memory and drives, and reassembling everything took about 2.5 hours.

The SSD drive came with a case. Before the hardware upgrade, I put the drive in the case, formatted it with APFS as the format scheme using Disk Utility, then downloaded the installer for Mac OS 10.14.4 and installed it onto the newly formatted drive. Then I removed the drive from the OWC case.

After the hardware upgrade, I put the old drive in the OWC case. I started the iMac from the new boot drive, said "Wow, that was fast!", and then installed all my software and all software updates on the new drive.

Finally, I ran the Apple Migration Utility to transfer just my data from the old drive to the new. Then I filed that drive away in a fireproof safe!

As an appropriately paranoid afterthought, I bought a new 2TB outboard hard drive, formatted it, and backed up the new configuration to Time Machine. I've since bought another to do the same thing.

Was it worth it? Yes, because I have twins in college! They, too, have Macs (2012 MacBook Pros). I've upgraded one of them to 16 GB RAM and a 1TB SSD, replacing the optical drive with the original hard drive. I'll do the other next month.

OWC will give you a rebate on used RAM sticks. I got $30 for the iMac RAM and $20 for the MBP RAM. (They test it before you get your check...)

no12mo

Did I miss something somewhere? Did you son come back with result of his attempt? If so, results. We need to know this before we proceed.

While I am not a current user of Cloud storage, I'm quickly becoming a convert. What I do is several generations of file backups, several generations of operating system clones. These are kept in a separate place from the main home, in a fire resistant room in hard drive storage spaces designed for that purpose.

Next, I see a cloud in my future. I'd post a picture but there doesn't seem to be a way to it in the reply mode.

DON'T fudge with the drive(s) in question. Spend the bux and go to a specialist who have the tools to recover the data. It's worth the money spent. After that, learn to clone if you don't know how to do so. Reinstalling a working OS is insane. Better to replace with a clone made from a previously working OS that you made from that machine. Drives / the cloud are relatively cheap in comparison to lost data

GrandmaG Loc: Flat Rock, MI

Good to know. Thank you so much for the detailed description. I have upgraded PCs before. Not sure if I would tackle such a project on the MAC, but I did double the RAM myself. That was easy.

I don’t have twins in college but I am retired and may want to avoid the cost of a new computer. I will copy this post for the steps to take if I get brave enough to do my own upgrade!!!

TriX Loc: Raleigh, NC

What ever happened to the OP and his data?

GrandmaG Loc: Flat Rock, MI

I was wondering the same thing. Very good question. However, in spite of their absence (or because of it), I got some answers to a similar problem that I had.

TriX Loc: Raleigh, NC

Yep, threads that pivot off in new directions can often provide both useful and interesting information.

therwol Loc: USA

It should be obvious. He sat down at his computer but found that his memory was lost, so he didn't know what to type.