CS800 C series has two ICs on each volume control board, and two ICs on the driver card. Two rocker switches on front, powr and fan speed. Volume control has pull switch.
CS800 B series has almost nothing on the volume control board, just two small transistors - and even they only have two leads connected on each. Only one IC on the driver. Same two rocker switches on front. No pull switch on volume.
CS800 A series. AS I recall these are mostly just like teh B, but some of them had only a push switch for power and a temoperature light for the fan speed. It looked like the push switch, but the light was justa light.
Yours is probably a C.