fan out of order (stupid test)

Since some days the upper fan of my M200 make some clicking sounds.

Before to change it, I wanted to test it by plugging the lower fan in place of the upper fan. I therefore inverted the connections on the PCB (fan 1 on PCB port fan 2 / fan 2 on PCB port fan 1).

It was definitely stupid, because when I activated the test drive of the fans from the panel display, there have been a dry noise and a toasty smell… which probably came from the bottom of the M200 (I’m not very sure)

Of course, since this manipulation the upper fan does not work anymore. Fans seems ok (tired but functional) because when I plug them into the PCB port fan 2, they works. But the PCB port 1 seems to no longer work at all.

In your opinion, which part that has roasted ?

Thanks !

First I'd check the unplugged fans using an external 12V power supply.

If they'r ok, I'd check the sockets on the printhead PCB using a diode tester or an ohmmeter (printer powered down), verifying them to each other; I think they should have almost the same value; there shouldn't be a short at all.

If the measuring shows differences between the 2 FAN ports, next the black long ribbon cable should be verified. 

Thanks for your advices ZX81, I will try this.

I checked all your recommendation, and the PCB was dead. Thanks again ZX81 !