Hi Will -
Thank you for the prompt response. Please see attached. I indicated with purple cut lines where I found two mistakes on the PCB which was very strange as these signals appear on the Eagle Board file but not on the Schematic file. Regardless, I cut these before placing the Photon on the board.
Also, I doubt they would have had any impact as the merely connected the JST connector directly to the analog pin as apposed to via the 3k3ohm resistor. Also, at this stage, there is nothing connected to the JCT connectors.
The layout is fairly simple as you can see.
- D7 connected to a NPN transistor to power a relay.
- D1-3 connected to RGB LED
- A5 connected to ACS current sensor
- A2-A3 connected to JST connectors for the purpose of connecting analog sensors art later stage.
The board is powered via the RECOM AC/DC converter supplying steady 5V to the Photon. The High Voltage traces are isolated from the rest of the circuit and only runs through the relay and ACS.
is it possible to fix this error or is the Photon damaged for good? It was working fine for about two months. Also day before while setting it up. Just decided to stop working 
ps: Init is a board problem, why does it not affect the Aruidno Uno? Bit reluctant to place more photons on these boards now, but need to get the product to the client.
Thanks again, appreciate the help!!
Friedl.