With a coin battery installed the card power-on LED will blink maybe 1 out of 10 times when powered on. The board  with the attached USB shield does not provide a connection to the host system. The host system does work with other Arduino boards along with the USB cable. Any help would be appreciated. Also this is the board with the coin battery. Does anyone know the part I need for the external battery connector?

TinyDuino  rev 9
USB Shield rev 6
Mac OS X 10.11.2

Hi- are you able to test the USB board on its own with another USB cable, maybe on another computer? You should have a new com/serial port show up in the Arduino IDE(or another program) as you would expect from the FTDI chip. If not, shoot an email to info@tiny-circuits.com

The LED is not a power on LED, it's a general purpose LED(the usual pin 13 LED)- sometimes the bootloader toggles it depending on the internal state, so it's not necessarily indicative of a fault with the processor if it doesn't flash.

Thanks,
Ben

I have another FTDI card (Sparkfun FTDI basic) along with other Arduino devices that operate with no issues. I have tried several USB cables with the same result. I will test the tiny-circuit on another computer and post the results.