A1200 doesn't power FDD properly.

[reno]

Hi there !

I have an issue with one of my 1200s. It's not powering floppy drives properly.
I've confirmed that with 2 different Chinon FZ-354 and a Gotek that all work in my other 1200, tested different power / data cables too. And when I power the FDD / Gotek separately with a standalone PSU, it works !

The main symptom is that the floppy LED stays on and nothing happens. It's even more obvious on the Gotek which doesn't power on.

I tested the floppy power header and it does read +5V and +12V with nothing plugged in.
However with an FDD plugged in I get just 2.95V on the 5V line and 0V on the 12V line (!). With the Gotek 2V on the 5V and again 0V on the 12 !

I've tested an original PSU and a modern 30W one (those repurposed Cisco PSUs), no difference.

Any idea what that might be ?

It's a 1D4 board and it's been professionally recapped last year. I'm not 100% sure I had ever tested the floppy drive before, so I don't know if the failure is new or not.

Thanks !