So I was hooking up my lcd to a circuit that I have been soldering. Shortly after I powered it up, the lcd popped, fizzled, and smelled bad (it hadn't displayed anything). The only thing I did differently is use 8 Eneloop AA batteries as the power supply. I did notice that the batteries were humming. Can someone tell me what when wrong so I can prevent with my next LCD?
The only thing I did differently is use 8 Eneloop AA batteries as the power supply.
At 1.5V each that means you fed it 12V, did you have a voltage regulator or was that directly onto the LCD power input?
Well I was using the arduino's 5v pin. I didn't hook the lcd right up to the battery. And they are 1.2v So its more like 9.6V
So where was the battery connected?
The battery was connected to the 2.1mm port on my arduino UNO
I did notice that the batteries were humming.
Maybe they didn't know the words to the song, so they could only hum it?
Drat you lefty you know I like to do that joke. 
So laptopman, you are saying that the LCD was connected in exactly the same way as it was when the arduino was powered by USB with the only difference being that you were powering it with +9V battery applied to the power socket?
If that is truly the case then it should not have damaged anything. However things do not make a noise like that without some sort of abuse so you will have to look more closely at what you did.
Get a picture up for some close inspection. Is the arduino still working?
The arduino works just fine. Nothing else was damaged in this incident. Also: Backlight still works fine, I am able to get the display to show random blocks if I press in certain areas. The backlight still works. Also, I hooked up the busted LCD (the 5v and GND might have been switched) and it popped and fizzled again- some smoke was released as well. I think it might have come from the LCD's PCB on a component labeled J1. Here's MY part of the circuit
EDIT: Emailed the company I bought it from, they emailed me back and said one of the things that could cause this was reversed current. Looks like that might be solved. They also offered to arrange a return/exchange. I highly recommend them (Microtivity on Amazon).
I think the wrong wiring is the cause..don't remove the wires, inspect them closely so that you come to conclusion and avoid the next LCD.. Check that you have right wires to back-light leds...i have blown away the back-lit one time in my life...and yesterday i blown away 16F628A pic, just due to wrong wiring... Check twice before powering up...
Khalid:
I think the wrong wiring is the cause..don't remove the wires, inspect them closely so that you come to conclusion and avoid the next LCD.. Check that you have right wires to back-light leds...i have blown away the back-lit one time in my life...and yesterday i blown away 16F628A pic, just due to wrong wiring... Check twice before powering up...
A rather inexpensive PC motherboard, and IR receiver, and an accelerometer on my part. Do the wiring on a breadboard.
Emailed the company I bought it from, they emailed me back and said one of the things that could cause this was reversed current.
But you said you powered it through the power jack. That has a protection diode to stop any damage from wiring the battery backwards!
How much smoke came out? If you get the smoke back in you might get her going again. Ive heard once you let the smoke out, its kaput:)