[Rajawi]

Hey all
we have a weird issue on chiron machine with 18i-mb5 controller, it suddently shut down and restart, the screen after complete restart just goes black with no display but still powered (fan is running, Pcb leds on...) we have to shut machine down to ne able to work with machine.
It dosnt happend in a specific position or block, it's random, sometimes during machining sometimes when it's on standby.
When it happend the spindle driver display error 24 communication error, after restart i check alarm history and i see :950 pmc system alarm. I checked inoming supply, 24v circuit didnt found something abnormal, well i'm stuck any ideas are welcome

[zavateandu]

from my experience and looking at the facts,it seems a 24v short circuit or a suddely consumption of a 24v line for a short period of time----for me all is related to 24v circuit,try first to replace the 24 power supply.

[Rajawi]

from my experience and looking at the facts,it seems a 24v short circuit or a suddely consumption of a 24v line for a short period of time----for me all is related to 24v circuit,try first to replace the 24 power supply.

I suspect the 24v circuit too, i installed a fuse just after the main 24v output but it didnt blow so i assume there's no short circuit, i dont have a spare 24v transformer so i'm trying my best, thanks for your answer i apriciate

[zavateandu]

I suspect the 24v circuit too, i installed a fuse just after the main 24v output but it didnt blow so i assume there's no short circuit, i dont have a spare 24v transformer so i'm trying my best, thanks for your answer i apriciate

i had once same restarts of nc when axis move in one location,i found a weared wire but also no fuse blown,was for a milisecond touching the ground,fuse had no time to blow.

[drdos]

You must understand how 24VDC works, when you have a short you don't typically blow a fuse, instead the 24VDC drops. Because the CNC is also ran from this 24VDC it turns off too. Intermittent makes it harder. What I try to do is find the short by testing all of the +commons to ground. Check all of the Fanuc outputs to ground too. You may find that the short only happens when the output goes on so it appears intermittent. Needle in a haystack first you have to find the haystack.