I have used my Raspberry Pi 3 Model B to control an attenuator. Long story short, it worked but after a while the CE0 Signal stopped going from logic high to logic low and instead just remained high. I changed my python script so that the other Chip Select - the CE1 is used, but it didn't even go to high instead remained low all the time.
The other pins kept working fine (Data Signal and Clock).
To verify the problem is not on the software - side I inserted the SD-card to a second RPi same Model and it worked just fine (like it did with the other one at the beginning). I am pretty sure nobody connected a voltage to any of those pins or did anything that could cause damage to the rpi.
I just can't find out how the Rpi broke and don't want to ruin another one. Are there any tests I could run? Any ideas on how this can happen?
I connected the attenuator and the Rpi on those Pins: 3v3; GND; GND; SPI MOSI; SPI CLK; SPI CE0
and then the RPi was connected to Ethernet(RJ45) and Power.
Thanks in advance