Intermittent Sonos ZonePlayer ZP90 fixed

One of my 6 year old ZP90 players (now called "Connect") has had an intermittent problem for several months. Sonos Customer Support were very patient and thoughtful but didn't see any errors in my diagnostic dumps, and didn't have a solution. Finally, it seemed to stay dead.

The problem was sometimes no audio would play from the house speakers. From the controller's view, everything was fine. I connected sensitive headphones directly to the jacks and could hear that the sound was actually there, just very faint. Also, sometimes while making a small change on a controller, like changing a queue entry, the sound would fade down, very briefly, and come back. I knew it was specific to this unit because two other devices continued playing elsewhere in the house, suddenly audible in the local silence.

Opening the ZP90 involves going into territory with very few DIY-serviceable parts. Here's how I opened mine: Lift the rubbery bottom corners away from the double-sided tape and remove four screws from the corner wells (after passing through the now-expired warranty sticker). Slightly lift the rubber along the sides and push small flat screwdrivers about 2 cm into the two snap slots on each side. Pull the shell off carefully because the volume/mute button panel is cabled to a circuit board. You can pull off the panel's connector at the board and set the shell aside. Undo three antenna cable snap connections, and one screw at the back of the top board. Lift the board off by rotating it slightly up from the front toward the back so the multipin connector to the lower board gently separates. Remove the power supply connector from the top board, then pull the board forward and up to let the ethernet ports clear their back panel opening. Reassembly is just the reversed steps.

A bulging, oozing capacitor on the power supply board caught my eye. (Others had black marks, but no leaks.) It was next to one lead of the high power switching diode. So, I expect it was heat damage, not capacitor plague.

I worked with the power supply board in place because removing it involves damaging the back panel to get to the screws. The hardest task was cleaning lead-free solder from the through-holes. I twisted the diode lead to the side to give a tiny bit more clearance from the new capacitor. The player now works fine. I guess the problem was board-wide voltage fluctuations as various circuits drew power, like the WLAN when controller state changes needed to be propagated.

Bulging capacitor. High power diode lead is on the right.