Hitachi seiki HT20J with 3299 ye-net i/o error

Hi,

I have a 1998 Hitachi Seiki HT20J, with Yasnac J300L control.

the issue I'm having is that sometimes when I press a number or letter on the keypad, the control react and go to alarm 3299 YE-NET I9/O ERROR, and machine go in emergency state.

Yaskawa suggest to pull and reinstall all the cables, and ribbons to clear corrosion from contactors, and possible loose cables. But after doing that, sometimes it fix the problem, and sometimes don't.

Any one here is familiar with this issue, that can suggest a possible permanent repair, as sometimes that completely screw up my day worth of work and I have to end up changing the set up to another open machine when possible.

Any input will be really appreciated.

Have a happy 4th of July every one in the States!!

Regards,

Cristian