Explorer 240 dead

My Explorer 240 has died. It is not responsive, no display, no output and will not respond to any of the reset procedures.

The only life that I can see on it is a flashing internal blue light which is visible through the side grill when plugged into the mains. This LED has a pattern of blinks which suggest an error code but I have been unable to find any info on this. This is a long blink when first connected and then a steady three short blinks. Any help would be appreciated.