sudomod

I am having a couple of problems. I soldered the PCB board to the Raspberry Pi Zero W and tested continuity (after testing it and it worked perfectly.) I then moved on to the screen board and screen combo. I ruined it last time, but the pad that I lifted wasn't needed (last time I just used a spare board). I did the best soldering job I could, tested continuity, and connected it to the PCB and turned it on. Immediately, a super high pitched noise (so high pitched my dad couldn't hear it, but my young ears could). The screen eventually never turned on, and the pi also didn't turn on. I unplugged ONLY the ribbon cable and the noise stopped and the Pi turned on. Has this happened to anyone before? I have included pictures to give you an idea about my soldering.

You likely have a shorted pin to GND, get some flux and use it then pass the soldering iron tip over the pads to clean up any bridges and solidify the connections. Make sure the tip is clean when you do this.

So I got flux today (as Helder suggested) and continued working on the screen board. The flux really helped in getting the joints connected. I plugged the screen board to the buttone PCB and then powered up the Raspberry Pi. This time, the Raspberry Pi's light kept on and there wasnt a high pitched sound like last time. But, the screen still never came on and stayed black for over ten minutes. I quadruple checked connections all thw way from the ribbon cable to the Pi and everything checked out. Anybody still got answers? Thanks!

I been trying to continue to fix it for about a week now to no avail. Please can someone help?

Test if there is power on the LCD pcb, test the VCC and GND pads on the for 3.3v. If it's not there could be a weak GND solder joint.

I tested it with my multimeter and it read exactly 3.3 volts.

So if you have power there now need to check voltage to the LCD itself. Here is the pinout of the LCD solder pads/ribbon:


Check that GND2 and VCC are not touching as that could be your short.

It all checks out yet it still doesn't turn on.

Unless you have another LCD or LCD board to try I don't know what else to tell you. You could have a bad LCD or a bad pi, I had someone send me their build and it turn out the Pi SPI GPIO got damaged by excessive heat (from customer) and would not work no matter what (Pi worked fine otherwise) so had to swap out the Pi then all was good.

Welp that sucks. So what would you recommend? Changing the screen or changing the pi?