I had the same issue with a DSP5200HC. It was the capacitors in that case as well.
Since it's an enclosed cabinet it does get warm in there and some of the capacitors used don't age well.
It seems to affect the smaller capacitors close to the driver transistors the most. (The smaller ones in the center of the board).
They originally have a gold color and turn dark brown/black due to overheating. You can see the larger ones on the edge have partly turned brown as well.

Pictures of board with capacitors turned brown/black.

Last edited by MagnusB; 2024-06-30 16:27.
Main: Marantz Cinema 50, Meridian 271, DSP7200.2, DSP5200HC, DSP5000 rears, Meridian 210.
PC/Headphones: Mytek Liberty II, Sansui CA-F1, Sansui B-2301, Sennheiser HD800, Kef R3