HT20SII Standby button will not turn on servos

Have an HT20SII with LX3 control. After you power up machine in back and hit the NC on button the screen comes up to Multi screen and after hitting the Operation soft key you hit the Standby button to finish powering up the machine. This is where my problem is. Pushing the Standby button does nothing. It is not in E-stop . Earlier we found that hitting the E-stop and releasing it you could hit Standby and it would work. But playing around with the E-stop button we got it to shut off so we replaced the E-stop. In the meantime we wired the E-stop wires together to run machine but after a few days off we have the same issues as before, no Standby button. Not sure whats going on. Every once in a while I'll get a Sync error at startup. Have to reset Diagnostic bit. Does anyone have any ideas on the problem?? Yaskawa wants me to send in entire card rack with the mother board. I did a ACGC generation but this made no difference.

Bryan, did you try tracing the standby sequence in the ladder to see where it is getting held up? Almost sounds like wiring or broken cables, but not sure. Take a look at that and let me know
John

Bryan... are you still having an issue on this?