I'm sure there's a dry solder joint somewhere on my display board, or perhaps a broken trace, but I'm having trouble finding it.

My symptoms are as follows:

- Sometimes the button lights will be on, sometimes they will be off.

- Putting pressure on the face makes the button lights blink on and off. Interestingly, it's just about anywhere on the face. At either end, in the middle, whatever.

- Sometimes the knob LEDs will be on, but the button LEDs will be off. This I find odd, because the knob LEDs get their on/off signal indicator from one of the legs of the button LEDs. So I guess that means the button LEDs aren't getting enough juice to light up, but they are getting enough juice so that the signal to activate the knob LEDs is working.

- When the button LEDs are malfunctioning, if I go into the dimmer menu on the player, it does not affect the brightness of the VFD display. Only after I press on the face to make the buttons light up, does the dimmer menu actually cause the display to change brightness.

I've tried to hit various solder joints on the display board with a soldering iron, places like surface-mount chips that looked like they were kind of dry. But the problem came back the next day.

I've checked and resoldered all of button LED connections, and the resistor pack. They all seem to be operating at spec. My hunch is that the problem is upstream of the resistor pack.

Any ideas where the dry solder joint or broken trace might be? Note: difficulty level= This is not a standard Mk2/2a display board, it was one of their early beta boards from back stock when they swapped me for a display that had the half-missing-picture problem. I have noticed its physical layout is different from the production boards, but most of the components are more or less the same.