If you can't connect to HPLC even when the below is true, then follow the steps later in this article:
When you turn the instrument power ON, run the CTI HPLC in administrator mode, you have the USB driver correctly installed, and can't establish the connection, then there are 4 possible problems:
a) The USB connector or PCB on the HPLC instrument is broken - continue reading the article;
b) USB cable is broken - try a different USB cable;
c) USB port on your computer is broken - try a different port or computer (don't forget to install the USB driver);
d) USB power management disables your USB port - read this article.
Broken USB connector
A. Check if there is a USB connection
1. Connect the HPLC to your computer via USB.
2. Turn on the HPLC instrument.
3. Go to Windows Settings->Bluetooth & devices->View more devices
4. You should see the HPLC connected to your USB and using the installed USB driver (Silicon Labs or FTDI).
B. Use RS232 connector
You can either use an RS232 adapter, or RS232 to USB cable. These are usually manufactured by FTDI or Prolific.
The RS232 to USB cable is included in your starter package as it is used to connect the precision electronic analytical balance to your computer. You can test/use the same cable.
When you use this cable you should be able to see it in Windows Settings->Bluetooth & devices->View more devices
If you are using a Prolific cable or adapter, you can check the same settings.
If after checking the above potential causes of broken connection and using the RS233 connection you still cannot establish a connection with the HPLC, please reach out. You may need a new electronic PCB.