Preamp kit P8084-1 trouble

P8084-1 preamp kit only has mono output from one output channel despite swapping output rca cables right for left or left for right- as well as swapping input cables… always just the one out channel working, nothing from the other. Any help? EDIT: the kit model is K8084… I’m not seeing how to post pics from an iPhone- I don’t have a computer online

You should post a clear picture of the top and bottom of the kit.