I had the SMD resistor, that goes to the Vcc supply pin, open up some on my dropping to supply voltage to the amp chip and the speaker would only work marginally but headphones worked perfectly. RD23 was at something like 77 ohms or some such and it was shutting down the chip. I just bent the legs on a thru-hole resistor and soldered it to the SMD pads and it has worked ever since.
David
WK4DS
WK4DS