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.