Just an update on this topic. Today my local dealer has had an X4 returned doing exactly the same thing. For the first time ever we managed to get it to re-boot on numerous occassions in the shop while I was playing. Usually you put these damn things on test in the shop and it works perfectly !This has at least put my mind at ease that I`m not alone with this problem although we can still find no logical explanation for it, nor can the Ketron lab in the UK. The DC output voltage remains a constant 8.6V. I now know of three other X4 modules that have this fault but believe there must be more out there. I`ll keep you posted !In the mean if anyone else has had this problem please get in touch,

Cheers

John