Der Generator ist funktionsfähig, allerdings schalten 3 Ventile im Innern nicht. Die Ventile sind schon dabei, man muß sie nur austauschen. Die Prüfung ist ganz einfach Versorgungsspannung am Ventil anlegen, wenn es klackt, dann ist es ok, ansonsten Stecker austauschen. Hersteller Metheson Tri-Gase Model NMH2-500 300 Watt 110-120 Volt / 230 V 50/60 Hz Innen sind schalten 3 Ventile nicht. Diese Ventile habe ich schon besorg. Man muß Sie nur austauschen und wieder zuschrauben Abmessungen 33x40x20 cm Versand 15 Euro Datenblatt findet man unter http://www.mathesongas.com/pdfs/litCenter/SpecEquipmentDataSheets/Chrysalis%20High%20Performance%20Hydrogen%20Generator.pdf The Chrysalis® II "HPNM" (High Performance No Maintenance) Hydrogen Generator represents a superior advance in the technology utilized to generate hydrogen without having to perform routine maintenance. The "HPNM" Hydrogen Generator Models incorporate an advanced dual-column purification system to remove residual moisture from the hydrogen gas produced, and the system automatically regenerates the column to eliminate the need for maintenance. This technology utilizes pure deionized water and does not require the use of chemical solutions to support the electrolytic dissociation process; this completely eliminates the need for a desiccant cartridge as a final purification step. The output of hydrogen is based upon instrument demand. A user-friendly digital display provides system operating status and diagnostic capabilities. The Chrysalis® II "HPNM" Hydrogen Generator produces a reliable continuous output of >99.9999+% pure hydrogen ideal for GC carrier and FID gases