Again - many thanks activa; I'm English, in France so I have to try to explain the problem to the chauvinistic french mechanic! Either I could get him to remove the unit and have a go, or I could risk him doing the repair! what do Citro charge for a replacement; any idea? Bound to be a fortune, I guess. Did you just reflow all the solder joints, or attempt to measure their resistance? thanks again for your support, jeffjohn France 44290.