To service the power supply and amplifier boards, you must remove the backplate of the subwoofer unit.
The Logitech Z906 is a legendary 5.1 surround sound system. It delivers 500 watts (RMS) of bone-rattling audio. However, many units eventually suffer from power failures, standard component degradation, or the infamous "three lights of death." logitech z906 service manual fixed verified
When reassembling the subwoofer plate, ensure the foam gasket is completely intact. The Z906 relies on a sealed chamber. Any air leaks around the backplate will cause annoying whistling noises during heavy bass tracks. Summary of Verified Component Fixes To service the power supply and amplifier boards,
Use your DMM in continuity mode. If it does not beep, the fuse is blown. standard component degradation
The Ultimate Logitech Z906 Service Manual & Repair Guide: Fixed and Verified