The old "glowing trim pot" trick...

[Jidis]

Here's another good one for people who like feeding voltages into random crap:

Just out of curiousity, I tapped my 5V Core supply across the two empty "pin 15/16" locations on one of those 2x40's today. The first time, I guess the polarity was backwards, so it did nothing but reset the PIC and reboot MIOS. I flipped the leads and hit it again. Unless I'm losing my mind, I'd swear I actually saw this thing light up (not the LCD, unfortunately). It only did it for a second, and I removed the supply a few times to see it again and make sure it did. I think I got it once more, and I'm pretty sure it was indeed from the pot, and not the bottom of the LCD. Looked like just on one side, and sort of weak. I even tilted the Core around, to make sure it wasn't a glimmer of reflection.

Is there any possible way you could get that from a pot, or make that resistive track heat up and glow? I figure it probably already had 5V somewhere.

I checked the supply pins to make sure they were live first by tapping a 5mm LED on them (with no current limiter). It lit quickly and made a small "snap" noise. I immediately remembered VilladonEnt's smell thing and held it against my nose. --- oh what a stink  (thanks for the tip ;))

George  ( remember this next time anyone wonders why I'm able to ruin a bootloader.)

Here's the type of pot that lit (sorry for the crappy picture). I think it was the contrast one, and it still appears to work OK.