<p>I have a new Photon S that I was able to print twice with so far. I've only been able to print the sample file on the Anycubic web site. When I tried to print my first custom object, it wouldn't read the file. It would just popup a message saying &quot;Failed to open file!&quot; I thought that my file might have a problem with it so I tried to print the sample file that I already printed successfully. Same error.</p>
<p>I read that it only supports 16 GB drives so I tried one and it didn't work. I asked people on the FB page which drives they are using successfully and the SanDisk Cruzer was recommended. I got two 8 GB versions of those. One worked intermittently, the other didn't.</p>
<p>I bought a USB tester to check the voltage and found that the voltage was 4.99 coming from an empty port. When I inserted the drive that worked, it dropped to 4.92. The drive that didn't work dropped to 4.93. I asked a fellow Photon S owner what his reads and it was 5.15 empty and 5.11 with a drive in it. My PC has a voltage of 5.20. All of these voltages are within the range of the USB standard but I think my sub 5 volt value has something to do with the failure.</p>
<p>Does anyone out there (an EE) know what's really wrong and has an actual solution or can tell me what I should look for? I know that there are a lot of guesses in the community. Stick with max of 16 GB. Try different sticks. Check internal cable (I also inserted the drive directly into the motherboard), etc. Communicating with a USB drive shouldn't be guess work as long as the drive is of good quality. The guy I asked uses a 32 GB stick which is the FAT32 limit for the standard Windows formatter.</p>
<p>Any help will be greatly appreciated. Thanks.</p>

CC BY-SA 4.0
2021-02-15T18:42:54.157Z
could be a lot... what format do the files have you want to print? What formating you have on the USB dongles?
Trish
CC BY-SA 4.0
2021-02-15T21:29:36.330Z
I do not have experience here. But I have read [Help, Photon S Failed to open File](https://www.reddit.com/r/AnycubicPhoton/comments/ggxw95/help_photon_s_failed_to_open_file/), and reviewed few other random threads, and I feel dizzy. Limit files to one? Rotate and reslice?! It seems that this printer is not properly prepared to read thumbdrives or filesystems? What I would advice is to try format with FAT and FAT32 using different cluster size settings...
octopus8
CC BY-SA 4.0
2021-02-16T00:21:18.723Z
I actually did full reformats on the drives. They're formatted to FAT32 with 16k clusters. The files are .PWS from their new Photon Workshop slicing app. @octopus8, isn't it dizzying? They're just posting things they tried before it suddenly worked and calling that a solution. There must be a flaw in the board or a flaw in the soldering of the board. I'm going to keep looking. I want a real, repeatable answer. Thank you for your comments.
Jim Berg
CC BY-SA 4.0
2021-02-16T00:23:37.117Z
I should add that I'm running the latest firmware and was able to print after the updates before it started failing.
Jim Berg
CC BY-SA 4.0
2021-02-16T16:09:53.467Z
Have you confirmed that the USB drives are genuine? Even major outlets have had problems with their supply chains. [5 Tools to Test and Detect Fake or Counterfeit USB Flash Drives](https://www.raymond.cc/blog/test-and-detect-fake-or-counterfeit-usb-flash-drives-bought-from-ebay-with-h2testw/) lists some utilities to check.
Andrew Morton
CC BY-SA 4.0
2021-02-17T03:28:39.677Z
There's no problem with them in a PC, not sure why there should be issues in this printer. Even when I copy files to it, I use the /v flag so the copy is verified.
Jim Berg
<usb>
Is there a known fix for when the Photon S has trouble reading from USB flash drives?
Jim Berg
# Is there a known fix for when the Photon S has trouble reading from USB flash drives?

(Asked by: username_0 on 2021-02-15)

I have a new Photon S that I was able to print twice with so far. I've only been able to print the sample file on the Anycubic web site. When I tried to print my first custom object, it wouldn't read the file. It would just popup a message saying "Failed to open file!" I thought that my file might have a problem with it so I tried to print the sample file that I already printed successfully. Same error.

I read that it only supports 16 GB drives so I tried one and it didn't work. I asked people on the FB page which drives they are using successfully and the SanDisk Cruzer was recommended. I got two 8 GB versions of those. One worked intermittently, the other didn't.

I bought a USB tester to check the voltage and found that the voltage was 4.99 coming from an empty port. When I inserted the drive that worked, it dropped to 4.92. The drive that didn't work dropped to 4.93. I asked a fellow Photon S owner what his reads and it was 5.15 empty and 5.11 with a drive in it. My PC has a voltage of 5.20. All of these voltages are within the range of the USB standard but I think my sub 5 volt value has something to do with the failure.

Does anyone out there (an EE) know what's really wrong and has an actual solution or can tell me what I should look for? I know that there are a lot of guesses in the community. Stick with max of 16 GB. Try different sticks. Check internal cable (I also inserted the drive directly into the motherboard), etc. Communicating with a USB drive shouldn't be guess work as long as the drive is of good quality. The guy I asked uses a 32 GB stick which is the FAT32 limit for the standard Windows formatter.

Any help will be greatly appreciated. Thanks.

**Tags:** usb
> **Comments:**
> **username_1**: could be a lot... what format do the files have you want to print? What formating you have on the USB dongles?  
> **username_2**: I do not have experience here. But I have read [Help, Photon S Failed to open File](https://www.reddit.com/r/AnycubicPhoton/comments/ggxw95/help_photon_s_failed_to_open_file/), and reviewed few other random threads, and I feel dizzy. Limit files to one? Rotate and reslice?! It seems that this printer is not properly prepared to read thumbdrives or filesystems? What I would advice is to try format with FAT and FAT32 using different cluster size settings...  
> **username_0**: I actually did full reformats on the drives. They're formatted to FAT32 with 16k clusters. The files are .PWS from their new Photon Workshop slicing app. @octopus8, isn't it dizzying? They're just posting things they tried before it suddenly worked and calling that a solution. There must be a flaw in the board or a flaw in the soldering of the board. I'm going to keep looking. I want a real, repeatable answer. Thank you for your comments.  
> **username_0**: I should add that I'm running the latest firmware and was able to print after the updates before it started failing.  
> **username_3**: Have you confirmed that the USB drives are genuine? Even major outlets have had problems with their supply chains. [5 Tools to Test and Detect Fake or Counterfeit USB Flash Drives](https://www.raymond.cc/blog/test-and-detect-fake-or-counterfeit-usb-flash-drives-bought-from-ebay-with-h2testw/) lists some utilities to check.  
> **username_0**: There's no problem with them in a PC, not sure why there should be issues in this printer. Even when I copy files to it, I use the /v flag so the copy is verified.  

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## 0 answers

