I have a trouble with a Siemens Micro-master 440 AC converter equipped with the encoder module. Sometimes, not regularly, the axis stuck giving the fault F090 (encoder loss) but everything seems to be OK. I've checked cables, connections, encoder, increased the thresholds and so on, but the problem still appears. Anyone have kind of experience with such trouble?

If has been working for years, it must to be a hardware problem. I would suggest the following:
* al ...