I ended getting my clock running reliable, apparently there is a slim chance that if your house is hit by a power loss during running it can correct the sd card - reason being is the card has a portion being updated every few moments to allow for randomness of the images shown. Therefore not just a card with files to read on it but a program that runs and constantly saving. If there is a power loss during the writing it corrupts the SD card and it needs to be re-flashed.
HERE is my step guide to help those with a MAC computer.
* you will need Parallels loaded on it to run Windows programs. For a while I forgot I had this on one of my design computers.
* you will need one of the Windows versions loaded on it - I have Windows XP on mine.
These are the steps in which I then did it - hope it helps people as the process is a little vague and assumes everyone is experienced in the process.
Step 1 - I downloaded the files
Step 2 - locate program and then the image file to be loaded to the SD card
Step 3 - While in XP on Parrallels insert the sd card into the computer and select windows screen because in apple mode it won't recognise the sd card (my screen also picks up my 3d printer)
Step 4 - Then I have an option - Initialize / Ignore / Eject - I trialed a few things but Ignore worked
Step 5 - Then in the select screen for copying the file to the sd - seen as a usb drive
Step 6 - Then start and gives you a warning, select Yes again
Step 7 - Programming took a couple of minutes and then says complete but also gives the option to start again - so don't push start. And being Windows running on a Mac there is no option to eject the card in the Windows mode - so remove the sd card (not much choice here)
Step 8 - Have clock connected to power but off on the button 4 to turn on (on j_m_ clock it is the very left button)
Step 9 - Insert SD card and it immediately turns on and boots up
Step 10 - Set time if the board has not been already set yet - if the clock was running and you have had to reflash the clock will maintain the time (if the battery is still installed)
Step 11 - Set sleep time
Step 12 - set wake time
then it should work , which it did for me..... on both sd cards..... hope that helps some people