[sdiy] Glowing diode on Casio CT-510 analog board?

[Benjamin Tremblay]

I do think the LED is related to power and possibly the LED was part of a unit test on the assembly line. 
I was able to get the CT-510 repaired last night. There’s a serious crack in the underside of that PCB, cutting off the audio traces going to the power amplifiers. 
One more trace went from the base of a transistor to the ribbon cable to the CPU. This seems like a muting/battery-save control line. After I restored that trace, things came back online and voltage was around 5.2V. Good enough for me.

Thanks for the spiritual guidance!
Ben