I have a surround sound JBL Synthesis pre-smp. It is behaving VERY erratically. Some MODE functions work and some don't at all. It doesnt seem to make much difference which inputs are used, some of the modes either give one channel or no channels however high the volume is put. Hall 1 used to work fairly consistently but now it doesn't seem to work at all. Similarly the tuner input (I use S VID1 for this) used to work on JAZZ but now it usually doesnt work much at all.
The right hand lights light up when you accress an input which is connected but with most modes, no sound comes out and with some modes, only one channel works (not always the same channel!)
The only mode which consistendly works is MONO ENHANCE (with a kind of falsified sound which you cant use with television on any talk mode which is how I have it connected) and suspiciously when you try to access one of the channels which isnt working on both channels, the non-working channel occasionally flashes on at full volume, indicationg a dry joint somewhere. But even this isnt consistent between symptoms, indicating that the unit isnt absolutely sure where any dry joint is.
Has anyone worked on one of these please?