Update - problem fixed! Downloaded the service manual & followed procedure to adjust screen cutoff voltage, which was too high. Everything perfect again

Update - no, the STB would not control the Humax, but I successfully achieved this with a Lintronic box.

As it says, my Beovision 3-32 is suffering from visible blue flyback lines when showing a blank raster. Actual picture colorimetry is still good, so I guess it's just blue drive level. Can anyone tell me how to get into the service menu to adjust it? I'm an ex-tv engineer btw, so quite happy with line-up procedures once I can access the menu

Will my Beovision 3 with stb module control a Humax 9200 PVR? There is an earlier model Humax box listed in the menu, but I don't know if the codes will be the same?