Nick I had the same problem. Most frustrating. Try this.
Take out battery, carefully prise red & blue wires from connector (remembering which way round they are located) use a separate charger to boost the batteries over a couple of hours. Reassemble the connector, insert battery, return to the cradle. Whilst in the cradle press the on button. Thats what worked for me. Hope it does for you too./
gazza
March 2007
howtomendit.com for free repair help, information and advice.
