Is anyone familiar with the MIDI circuitry of an ETC Ion?

[alistermorton]

We have a Win 7 Ion classic which serves us well. We use it connected to a Mac via midi to interact with Qlab. We could use OSC, but midi has always been more reliable for us (we've had dropped go commands over osc).

The midi ports appear to have died. We've tried to get it booked in to our disti for troubleshooting, but they have a 6 week lead time on the workshop, so we were wondering if it was likely to be a simple chip replacement we could look at doing ourselves. 

Does anyone know if the midi circuitry on the expansion card has an easily replaceble device, or even if there are spares inside. There appear to be spare drivers for the DMX ports, so we were kind of hopeful.

Thanks.

[Brian]

A MIDI input normally runs into an opto-coupler, often a 6N137.

[alistermorton]

OK, that's worth looking for; thanks, Brian.

It's also not to outputting anything, so I'm wondering if there's a single chip that handles input and output.