All power supplies tripped on high conductivity of the cooling water < 5 MOhm, It is not clear if this was caused by a spark or vice versa. According to the strip tool for this signal the resistance of the water went up. There might be a fault in this signal. I do not have permission to force this signal so I keep the heaters off. We should revisit the interlock conditions, this signal should not be included in the interlocks for the heaters. Both target and tube seem to be still o.k. As I do not want to destroy the target I keep the heaters off and restart the high voltage only.