Hello
I got a few of these Chinese Matrix display based on the Max 7219 chips, but none of them is working. The connection seems to be correct. All CLK, DIN AND CS pins are tied together and CHIP 3 DOUT going to chip 2 DIN, chip 2 DOUT is going to chip 1 DIN, CHIP 1 DOUT is going to chip 0 DIN.
As a matter of fact, I tried a lot of library and the result is always the same (see picture 2). In this example, I'm writing "1 9 7 3" string on the display. Does someone have an idea what's going on? TIA