Ultra Fit USB 3.0: Excessive Heat

i would like to share my experience with Ultra Fit 3.0-16GB.I’ve used it in my Sony Car Audio System. But after few months i’ve found the heating issue. It became so hot just few minutes after inserting that couldn’t be touched on the metallic portion.Few months later it started showing problems like, the flash drive is undetectable after getting heated just after inserting it. It becomes a useless one. SanDisk should solve the problem or stop selling this product.

So has SANDISK offered to give anyone a 2.0 in exchange or anything else? I know this is a OLD post but just got mine about a month ago & just tried to use it for my motorcycle stereo. ITS INSANELY HOT & I will not use it with chance of doing damage. I have the 64GB 3.0 it gets crazy hot in no time flat in a stereo, my pc or my mac!!!


Well, well, well. Yet another long-running thread about an unresolveable problem… :smileyvery-happy:

I went through the ‘write-protect’ saga with the Cruzer Blades. I still maintain they’re good little drives for the price, as long as you don’t try to use them to extremes.

As for the Ultra Fits…yeah, the little buggers do run hot, it’s true. But even in a USB 2.0 port, the transfer speed is nothing short of astonishing. And in a USB 3.0, it climbs into the stratosphere…

I’ve got 2 of the 32 GB models. I’ve got at least 3, if not 4, of the 64 GB models. And in the last year, I’ve splashed out on 3 of the 128 GB jobs, too. (These latter three are formatted to ext3; one is used as a miniature NAS in our router, and the other two are used as permanent ‘external storage’ in a 15-yr old Dell Inspiron laptop running ‘Puppy’ Linux. They’re not used for system stuff - although Pup’s mode of operation keeps system read/writes to an absolute minimum anyway (it’s one of these distros that runs totally in RAM, and only writes config/settings to the flash drive periodically) - but simply for data storage, to supplement the 64GB SSD ‘upgrade’ that hosts Pup itself.

I’ve tried these in FAT; ex-FAT, and also NTFS, in addition to Linux formats. Even BTRFS. Doesn’t matter what format you run 'em under, they will get very hot. One of the other posters, several pages back, hit it on the head when he/she stated about the laws of physics prevailing; cramming an enormous number of transistors into a teeny space, the heat produced has got to go somewhere. And in this case it’s the miniscule metal shell…which, let’s be fair about this, does do its best to try and dissipate that heat, despite having its work cut out from the ‘get-go’! :confounded:

The QC guys must have determined these weren’t going to get hot enough to cause major problems…although joeydee’s pictures don’t exactly inspire confidence, do they???

(I also have a Cruzer ‘Fit’ (the 16 GB model)…which runs as cool as a cucumber. Through I would dispute that those tiny ‘cut-outs’ have got very much to do with it…it’s simply due to a much lower transistor count.)

The news about the far higher power-draw is enlightening, too… :dizzy_face: And a printed warning on the packaging that heat production may occur regularly would go a long way to help matters…bearing in mind that high transistor count AND the astonishing performance.

Ah, well. Carry on regardless!

Mike. :wink:

I’m running both the original 128GB Ultra Fit(s) and the new 256GB Ultra Fit(s).  Aside from the typical heat issue, I’m noticing dropped connections, particularly when using USB 3 transfer rates.

I’ve returned two of these for replacement and have RMAs in for another two.

I just found this thread, and while I’ve seen my Ultra Fit getting quite hot in the past, it seemed to work mostly fine nevertheless.

However, having just found it about its torn pin (as I posted in http://forums.sandisk.com/t5/All-SanDisk-USB-Flash-Drives/Ultra-Fit-not-working-is-the-4th-USB-3-0-pin-normal/m-p/366254), I wonder if any of you has a similar issue? I had never noticed it before, so I wonder if it could be related.

Have six of them. Using 16 and 32 GB versions.

Holding three of them in 3.0 slots in my motherboard from 2015 to date of this post. Almost never removing them. They work well.

One is plugged into 3.0 slot in my Monitor. One is in Raspberry Pi 3 B+, one in Car radio.

ALL OF THEM ARE HEATING SO BADLY! But I don’t know if that heating affects performance, except that one in my car.

I only experience problem with that one which is in my car. Only in heat in summer. When air is very hot.

Radio’s USB port is getting so hot and music is stopping playing. Need to plug device out and wait until is cool.

But they are still working fine.

I Googled this topic because I was really confused after all these years of usage.

This is what I can share with you. Cheers :slight_smile:

well you guys been lucky here…i once needed to remove my computer case and remove flash drive cuse it got melted into usb port and got stuck there.used screw driver and brute force to push it out.
got both agter cleaning with 90% alchool what is meant for cleaning for electronics(like thermal paste).

My 2nd Sandisk Ultra Fit 128GB 3.1 has now also failed after 3 months with a write protection error and also got extremely hot, even when using a short usb extension cable, as I didn’t want it melting my Nvidia shield tv usb ports. When are Sandisk going to acknowledge that there is a problem with these usb heaters, sorry I mean sticks.

July 2019. I’ve just fitted a 128GB Dual Drive to a Samsung Galaxy S9 Plus using the USB Type-C power/data connector port.

Within 5-10 minutes, the Dual Drive became so hot that I had to protect my hands to remove it.

My thinking is that Samsung have not provided any power regulation to protect peripheral devices from receiving too much power from the 3500mAh battery fitted in this 2018 design smartphone.

A quick look at Sandisk’s Dual Drive “compatibility” list – at http://www.sandisk.com/dualdrive-c – only lists older smartphones, which had lower mAh batteries. And I doubt very much that Samsung considered ‘regression testing’ of the Type-C USB port for peripheral power compatibility when they released their newer, higher power battery, 2018-19 smartphones.

I’ve submitted an alert to Sandisk and, to their credit, they’ve escalated my report, and are currently investigating the issue.

Meanwhile, if anyone has the appropriate electronics skills, it’d be interesting to measure the Amps power being output by older smartphones versus 2018-19 phones with significantly higher capacity batteries.

I believe you will find that it isn’t poor design, but rather that the Ultra Fit are USB 3.0, whereas the Cruiser Fit is only 2.0.  USB 3.0 uses more power, but it still doesn’t seem as if they should get that hot.  I have the same problem, and perhaps it is a design flaw, but we can’t compare it with the Cruiser Fit, because one of almost 10-times faster in file transfer speed than the other.

I recently bought one SanDisk Ultra 128 GB dual OTG Flash drive, with a C type connector on one side & a standard USB connector on the other side. It’s capable of USB 3.0 speed.

When connected to my Samsung S8 mobile using its type C connector, the flash drive was getting very hot within a short time. I use it to play music (wav files) & it started to heat up even before the first song ends. By 10 minutes, it used to become so hot that I could not touch it without being burnt.

So, I returned it & got a new one but again the same problem.

This time, I connected to the mobile using the standard USB connector on the flash drive & a type C adapter that came with the Samsung S8. Lo & behold, there was absolutely no heating problem whatsoever even after playing for hours.

Does this mean that the problem is with the C connector?

Users of this flash drive, please give me your feedback.

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I have similar hot USB experience. I used a new SanDisk Ultra Flair 128GB to be connected permanently to a TP-Link Router (Archer A9 AC1900). The router is scheduled by a power socket timer to power off at night & on in the morning. Every morning, about 1 hour after the power on (without manually accessing any data on the usb), the 128GB usb become obviously hot (not just a little warm). And then if I unplug & re-plug it physically, the hot vanish quickly and it won’t become hot again even after several hours. (I tried safe-remove from the TP-Link software-wise, without unplug, but that won’t stop the flash hot). This experiment have repeated for 4+ days, and the result is the same. I tried another brand’s USB flash, it doesn’t become hot if it is plugged in before the router re-power-on. Thus, it seems there is a hardware design flaw in the SanDisk flash hardware controller.

Supplementary info: My 128GB USB is quite new (second half of 2019) and light-use, and I haven’t re-formatted it.

Additional info: the TP-link router port is a USB 2.0 port.

Bought three of these Sandisk Cruzer Fit 64GB USB3.0 drives recently and was horrified to see how hot they became when plugged into a USB3.0 socket - the metal parts of the stick were VERY hot after a few minutes operation. When I pulled one of these sticks out - my finger tip felt like it had touched the metal surface of a boiling kettle !!


Sandisk have a problem with their usb 3 implementation. They have had this problem for at least 5 years judging by this forum.

They offered me a swap for an Ultra Flair. But I am reading that they too get too hot to touch!

I am using the Ultra Fit 64GB on a short extension lead  It runs a bit slower but it won’t cook the laptop port.

I also have a 64GB Ultra Dual Drive usb 3 which is actually faster than the Ultra Fit and is tollerably hot. The much larger plastic body could be the reason?

Other brands of usb 3 flash drive dont have this heat problem. Why are Sandisk not addressing it?

I currently own 4 Sandisk flash drives, all of them are Dual (3 x micro USB and 1 x USB C) with capacities of ‘32’, 64, 128, 128, respectively. All of them are bare, the plastic housing just stopped working because of the fragility of the connection between the plastic housing and the tiny piece of plastic on the metal frame, so I had to strip them down.  Because of this I am constantly burning my fingers when I remove them from either the USB hub or the PC.

I think it is high time Sandisk addressed this problem and need to go back to the drawing borad to engineer a usable, stronger device.

P.S. I am about 90% sure that the 32 GB is a Sandisk. If it isn’t then Sandisk isn’t the only company with this problem.

Yes it appears that only Sandisk have an overheating problem with their USB 3 flash drives.

Their USB 2 flash drives are fine.

This issue has gone on for at least 5 years and they have done nothing about it.

I have a 3" USB extension lead which I always use with the Ultra Fit. It slows it down a bit, but it won’t destroy my laptops USB 3 port.