New Build LCD Display Issue

[JNimety]

Hi all. This is my first HeaterMeter Build. I seem to have most everything soldered correctly and working. My Pi 3B+ boots and I can access the web page, read temps, flash firmware, etc. However, my LCD screen remains blank. The back lighting works and the 3 leds flash when first booting, but nothing shows up on the display. I've searched the forums and have been over the recommended procedure of adjusting the contrast, checking continuity of pins D4-D7, GND, 5V, LCK, SCK, M0, etc, and testing for shorts. Everything seems ok. I did initially install the shift register facing the wrong direction. Is it possible that it is damaged now?

I'm new to soldering and electronics and I'm looking for any help to point me in the right direction. Thank you!

 

[Gary V]

I did the exact same thing on my build back when. I replaced the lcd driver chip, IC3, on the pushbutton board and I was off to the races. I suspect yours is damaged.

 

[JNimety]

Thanks! I already have a replacement on the way that arrives on Monday. I'll report back after I get it installed.

 

[JNimety]

Woot, replacing IC3 worked. Thanks!

 

[Bryan Mayland]

Nice work! Yeah unfortunately putting the these 74 series chips in backwards tends to be instant death for them.