The WQB repair system upgrades the Weller product range in the SMD tool sector. A well thought-out design concept combines reliability and maximum process control with ease of use and technicaly mature detail solutions. Usefull accessories increase the possible uses of these repair work stations. For the universal circuit board repair of SMD components, it is necessary to preheat the circuit board effectively from below and from above to precisely heat the components to be repaired to the reflow temperature as well as to reliably control the process. On the WQB 4000SOPS the temperature regulated 2-Zone infrared bottom heater provides rapid warm-up and homgeneous substrate temperatures. The hot air top heater, with digital control electronics for temperature monitoring and regulation of the air flow rate, facilitates the finely metered supply of heat to the components. A temperature sensor placed directly in the hot air nozzle efficiently regulates the top heater and thus provides max