External hard drive not showing up on my Mac. What can I do?

hafix_roh

hey all, new here so sorry if this is the wrong place or something 😅
I plugged in my external hard drive this morning (it’s a 1TB) and it's just... not showing up anywhere. not on the desktop, not in Finder.
was working fine like last week, haven’t dropped it or anything. only thing I did was update macOS a couple days ago (running latest version now on a 2019 MacBook Pro). but everything else is working fine so not sure if that’s the issue? would really appreciate some help.

HopeInSleep

Did you try Googling it yet? Not trying to be snarky,just saying, the whole Mac not recognizing external hard drive thing is super common. There are literally thousands of threads on it out there. That said, start with the basics.
When you plug in the drive, do you get any lights on it?
Can you hear or feel it spin up at all?
Like, is it physically doing anything?
Because if it’s totally dead (no lights/ noise/vibration) then you’re probably dealing with a hardware failure, and there’s not a whole lot you can do on your owm.

hafix_roh

HopeInSleep yeah it lights up and I can feel it spinning when I touch it so don’t think it’s dead?
def not making any weird clicking noises or anything either. so the hard drive is alive just not showing up on my Mac.

SocialImpactCoder

First thing anyone should do when an external drive not showing up on Mac is open Disk Utility: Press Cmd + Space, type “Disk Utility,” and hit Enter. Check if your external drive shows up in the left-hand panel under “External”, If it’s there but grayed out or not mounting, the issue might be with the partition map or file system. Let us know what it says.

hafix_roh

SocialImpactCoder just checked. yeah, it’s there under “External” and says “JMicron Tech Media” here’s a screenshot:

SocialImpactCoder

hafix_roh that screenshot says a lot. That’s an uninitialized disk (no partition map / no file system) - which is why your Mac can see something’s plugged in, but can’t actually mount / read anything from it, so it won't appear in Finder. Happened to me once when I accidentally yanked a drive out mid-transfer. Could also be from a bad format, corruption, things like that. Quick question, did you try to format or erase it recently, or maybe unplug it without doing a proper eject?

MmkrkdlGelo

hafix_roh Had the same thing happen to me a couple yeras back with a 2TB WD, power flickered during a transfer and when it came back up my Mac wasn’t recognizing the external hard drive, just showed it as uninitialized like yours. If you care about the data on it, your best bet is to try recovering it BEFORE you do anything like erasing or reformatting.
I used Disk Drill on mine. The free version scanned everything just fine, but I did need to upgrade to actually recover the files. It was worth it though got back almost everything, even the folder structure.
Once I had the data, I just erased and reformatted the drive in Disk Utility and it’s been working fine ever since. That’s my suggestion. If it’s not a physical problem, you should be able to fix it on your own.

DanyOrtega89

hafix_roh You might also want to check the SMART status just to rule out any hardware issues. Could be the drive, could be the enclosure acting up. If the adapter board inside is failing, it won’t pass along the right info to your Mac, and you’ll see weird stuff like uninitialized drives. Definitely sonthing worth checking.

HopeInSleep

+1 on recovery before you do anything else. Don’t rush to click “Erase” (unless you’re cool with losing whats on there) I’ve had good luck with free tools TestDisk/PhotoRec, kinda tricky to use, but can do the job.

TestDisk can actually repair the partition table in some cases, so you might not even need to wipe the drive if it’s just corrupted and not totally nuked. If you’re curious, the official TestDisk guide walks you through step-by-step.

In short, you run it as sudo in Terminal, pick your drive, and let it scan for lost partitions. If it finds something, you can often restore it right from there. Also used R-Studio a couple times, solid tool but kinda pricey.
Bottom line- get your stuff off the drive first, then you can mess with formatting.

MmkrkdlGelo

DanyOrtega89 this, @hafix_roh maybe try isolating whether the issue is with the drive itself or the enclosure. Can you take it out and test the bare drive in a different case or a SATA dock?

hafix_roh

@SocialImpactCoder def didn’t erase it, but yeah, can’t lie, I prob unplugged it without ejecting a couple times if I was in a rush 😬 there’s definitely stuff on there I’d rather not lose if i don’t have to.
@MmkrkdlGelo don’t have another enclosure or dock lying around to test it with sadly.

appreciate all the tool suggestions, maybe I try TestDisk&PhotoRec. so if I scan it and recover the data I just hit erase in Disk Utility after that and that’s it?

@DanyOrtega89 how do exactly do i check SMART status again? what should I look for?

DanyOrtega89

hafix_roh You can check the SMART status in Disk Utility just select the drive from the sidebar and click the “Info” button at the top right. Then scroll through the list until you see something labeled SMART status. If it says “Verified,” the drive is considered healthy. If it says “Failing” or gives a warning, there’s likely a hardware issue. There’s also third-party software for macOS that can read SMART data, but I’ve personally never bothered with it.

MmkrkdlGelo

hafix_roh Yeah, after recovery, just go into Disk Utility and erase the drive to get it working again.
Click on the drive name, then hit the Erase button at the top. You’ll get a popup asking for a name, format, and scheme.
-For Format, pick APFS if you're only using it with Macs, or exFAT if you need it to work on both Mac and Windows.
-For Scheme, select GUID Partition Map (that’s the default and works fine).
-After that, click Erase and let it finish. Should only take a few seconds if the drive’s healthy.

Edit: By the way, Disk Drill has a built-in S.M.A.R.T. monitoring feature. If Disk Utility doesn’t show that info, you might want to try it, or use an app like DriveDx. I’ve used both pretty good. But for external drives, you’ll need to install a special driver for either app to see S.M.A.R.T. data. That’s explained clearly here for Disk Drill and here for DriveDx. Without the driver, they probably won’t show anything for external SSDs/ HDDs.

hafix_roh

DanyOrtega89 just checked it, mine says “Not Supported” lol

DanyOrtega89

hafix_roh “Not Supported” usually means the enclosure isn’t passing SMART data through to the system. It depends on the USB-to-SATA bridge board inside -some just don’t support it at all. Not uncommon with cheaper/older enclosures.

KindnessCatalyst in 99% of cases, repairDisk won’t actually fix anything. You’re better off skipping straight to something like TestDisk.

Nonprofitech

Just remembered something, are you connecting the drive through a USB hub, or straight into the Mac? I’ve run into that exact external hard drive not showing up on Mac issue a couple of times when using a hub(the drive would power on, maybe even show up in Disk Utility, but it wouldn’t mount properly). Plugging them directly into the Mac fixed it every time, looking back it was probably just a crappy hub.

KindnessCatalyst

you could also try running a repair from Terminal:
diskutil repairDisk /dev/diskX
(make sure to replace diskX with whatever your drive’s identifier is, like disk2 or whatever you saw in Disk Utility)

hafix_roh

@Nonprofitech nope, not using a hub just plugged straight into my Mac’s port.

trying TestDisk right now... baaaarely made it through the manual
but it looks like it’s scanning now fingers crossed 🤞

0neWire

hafix_roh If I’m being honest, I wouldn’t start with TestDisk right away, at least not without a backup in place.
It’s a powerful tool, but running repairs could make things worse for your files. Personally, I’d image the drive first or at least try recovering any critical data you really care about before doing anything that modifies the structure. Once you have a copy or the important stuff out, sure, give TestDisk a shot or just erase the drive clean and start fresh.

hafix_roh

sooo... TestDisk actually worked 😳
spent a while poking around (the terminal is bruuutal)
but I followed the steps and it somehow found the lost partition.
It restored it and everything showed up, can’t believe it I thought it was gone for sure.
huge thanks to everyone who helped here 🙏
tried a couple apps for SMART but none showed anything, guess it’s just my drive being weird.
got it for cheap so yeah... probably got what I paid for, gonna be way more careful with it now.