About a month ago, half of my resource monitor display started to go bad. It started with vertical lines not showing up, and went downhill from there. Applying pressure to the back of the PCB sometimes helped at first, but then it had less effect as time went on.

A few days back the display completely failed. I borrowed a spare one from a friend, and re-soldered it up, and everything is working again.

I have no proof that this was the cause, but I was driving the contrast pin with PWM directly without any RC filter. I wonder if that, over time, contributed to the failure. Even though I have no proof of it, I have since switched to a potentiometer instead of PWM for contrast (and while I was at it, a fixed resistor instead of PWM for brightness). It no longer has software controlled brightness / contrast, but I picked a resistor value which gives me the right brightness, and manually adjusted the potentiometer to match.

Anyway, things are back to working again. Here's to hoping that this new display lasts longer than the previous one. They are from the same eBay seller, so if it was not PWM that was the cause, chances are it will fail again: this will tell me whether the display itself is just bad, or whether I was using it wrong.

Cheers