Cinese laser engraver problem
Reply with QuoteA packing foam peanut tied to a piece of cotton and suspended close to HV input at rear of tube will move toward the connection if there is HV output which may indicate tube problem.
Cheap chinese imports often arrive with little life i.e. gas and catslyst remaioning in tubes as they decay during lengthy ship journeys and warehousing why only direct from factory tubes are normally available if you stock them they are decaying all the time. they are also very succeptable to over driving to many milliamps or overheating temp of coolant over 75 deg F which can kill tubes in less than an hour.
