I'm trying to narrow down where the problem might be. The button lights are not lighting. This is even when I've got the knob-light board disconnected. Yes, I've checked to see that Hijack says Button illumination max.

Interesting thing. When I use my multitester to test continuity between the upper left wire of the top button LED (the place where I've soldered the knob-board activation wire) and ground, all four buttons light dimly just from the voltage from my multitester. So at least I know the LEDs are good. (Edit: This only happens when the player is plugged in.)

I get 5 DC volts testing between any point on the resistor pack (or any of the traces or test points or other nearby components it's connected to) and ground. I test about 550 ohms resistance between the common side of the resitor pack and any of the four resistor-side legs of the button LEDs. The solder points on the resistor pack and all LEDS seems fine.

Where else can I test?