sorry for my late reply, lately i change my cable route. i take it away from motor cable and fan. but i did not changing the cable. this morning i got random change tool once again.
this night i already changed the cable. hope this problem really dissapeared
i will update it after several days
@Phaedrux the problem still show up. at lately it more often. i have change the cable to STP lan cable used 4 cable only. i also make it shorter the cable is 50cm long only, before is 1.5m a weeks ago my problem is not occurs often. very rare but sometimes happened but this week it show more often.
is there any trigger event that when it change from active to standby i can forced it back to active?
any way to do it?
@dc42 any help about this. i have disperate to solve it with cabling 
@wilriker
tested without paneldue and print ok in several print part and in 5-6days trial
connect the paneldue again and it random change tool again
i used blv project for the printer. and looks like the led cable is cross with paneldue cable event i already used shielded cable and ferit.
now i forced to select tool 0 and cannot change to another
next try is separate and reroute the cable of the led at the front cover. and get messsage if the system change the tool accidently.