RP2040 Zero not recognized

[jeffbrl]

I'm almost certain my issue is the operator induced rather than the software.

I built three RP2040 zero-based PicoMemCards loaded with https://github.com/dangiu/PicoMemcard/releases/download/v1.0.0/PicoMemcard_RP2040-Zero.uf2. I am using dangui's v1.3.1 PCB and his enclosure. I loaded the non-blank memory card image from this repo. The name is unchanged. Using the diagrams in the README, I verified continuity from the Zero's pins to the pads on the PCB that interface with the PSX.

I am inserting the PicoMemCard with the Zero side facing down.

On all three PicoMemCards, the PSX does not recognize the PicoMemCard. The green LED is lit.

I'm at a loss for how these the zeros could have continuity and the correct software loaded and not function properly. I feel as though there is something I am doing wrong that may be obvious to others but not me.

May I get tips for additional troubleshooting?

[Haldrie]

It looks like you have some cold solder joints in the picture. It may have continuity but maybe the connection is weak and not keeping up with the PS1's timings or when you tested continuity your probe was making contact with the pad under the RP2040 and not just to the RP2040 itself or pushing your probe made contact where there isn't one if no pressure is put on it. Try adding some flux and reflowing the solder and see if that helps any. The attached picture is one of 5 that I have built using the microSD module and the pads you see soldered are the only ones that are connected to anything. Pins 26-28 are connected to the button pads on the board for use with PicoMemcard+ code but I recently learned from the developer that he never added any code to take advantage of them...yet.