Hello Rodrigo,
Is the ASIN of the product you are referring to B00E8D7XYG?
If yes, the product (ASIN: B00E8D7XYG) is DC to DC Boost Converter. The electric wave of DC is nearly like a straight line. Basically, there is no square wave.
Besides, the output voltage range is DC 12-80V. If you need the output voltage of 100V, this product maybe not suitable for you.
Hope this will be helpful to you.
Best regards

Hello John Northup,
Thank you for your reply.
Have you tried to only connect a LG phone to the output?
If not, please try it and see if there is a display or not.
According to your description, the input is the USB 2.0 from desktop computer.
The power of the USB from a computer is very small and it is hard for it to charge for both a LG phone and Nexus pad at the same time.
Therefore, if the input is the USB 2.0 from desktop computer, it is better that you charge only for the phone or the pad at a time.
Hope this will be helpful to you.
Best regards

Hello Chris L,
Thank you for purchasing.
Could you please tell us your order ID or the ASIN of the buck converter you brought?
It is better you can tell us more details of how you operate the item, such as the input voltage/current, the wiring. We sincerely hope that you can send us some photos of the installation.
Waiting for your reply.
Have a nice day!
Best regards

Hello Marc,
Thank you for purchasing.
Actually, the module accept power via the battery +/-. The USB power is charged for the battery. The module should not be charged by USB plug without the connection of battery, or it will appear intermittently promote sound because of the charging protection function.
If you only got red flashing light, that means the module stopping searching Bluetooth device, you can try to wire the module again.
Here is the datasheet of the module Datasheet_B016Y1850U
Hope this will be helpful to you.
Best regards

Hello Edward,
Could you please sent us the ASIN or the product page of the product you are referring to so that we can provide more accurate answer to you?
Thanks

Hello Garrett,
Thank you for sharing your experience and the suggestion.
We are glad that the item can meet your demand.
If you have any questions, please feel free to contact us, we are always here to assist you.
Best regards.

Hello John,
Thank you for your message.
Could you please send us an email to service at droking dot com to tell us more details of the your operation, such as the input voltage/current? If you can, we hope that you can send us some photos of the problem details.
With your help, we consult to our technician and find out a solution more effectively.
Beg your understanding.
Best regards.