RPi Blue&White 16x2 LCD+Keypad - no characters?

[jesse_m]

This was my first attempt at soldering, so 1) I'm guessing I screwed something up, and 2) be kind. :)

Everything went together just fine, but when I run the test Python script, the display lights up (blanks out for the Red and Green tests as expected), but no characters display on the screen. Adjusting the contrast has no effect on the display (nothing to contrast against I guess). All the buttons seem to work as they're displaying correctly in the terminal. Any thoughts?

Images attached.

Thanks in advance!

[adafruit_support_rick]

Overall, the soldering is pretty good, especially for a first timer!

It's a good sign that the buttons are working. That means that the problem is somewhere between the MCP23017 chip and the LCD.

These solders look a little light. You can see that the solder hasn't flowed all the way around the pin and across the pad. I indicated four, but you should check all of the solders in this row:

plate solders.png (931.5 KiB) Viewed 408 times

The solder should flow completely across the pad, and should flow up the pin, like this:

[jesse_m]

Ok, second pass on those connections, but no change in the result. Any other connections I should touch up maybe?

[adafruit_support_rick]

Ouch! Everything looks good - it's not a soldering problem. It's probably a bad LCD, but I suppose it could also be a problem with the MCP23017 chip. I think we'll have to replace the plate. Sorry about that.
Please email [email protected] with a link to this thread for a replacement LCD plate

[jesse_m]

No worries. Thanks for your help!