I have a johnford vmc 1120 with an umbrella type tool changer. it hangs in the middle of a tool change, either when the carrosel comes over to grab the tool, in which case it doesn't know it's grabbed the tool so the tool number doesn't change, or after it grabs the tool and drops down, in which case the tool number changes. In either case the only way to clear it is to manually remove the tool and power down the machine.Any ideas where to look to fix this problem?Thanks