Mimaki CJV150 - preheating don´t STOP - always heats up, even in standbuy

[Plotter-FIX]

Hey guys,

a Mimaki from one of my clients did not stop heating. The Heater is already turned off totaly in the Menu and the machine is also heating in the standbuy menu.
So he and me are scared of to much heat as it is heating up until 76 degree... so he needs to turn of his machine and is not able to print anymore.

Did someone of you alraedy had that kind of problem?
My fist step would be saving parameters and update the machine to the newest firmware as the version right know is quite old.
But to be honest i don´t think that this will help to solve the problem.

 

[netsol]

not familiar with that machine, but, it's a simple circuit
there is some sort of power transistor or solid state relay switching power to the heaters
in simplest terms, either the switching device is shorted (probably a solid state relay)
or a thermistor is defective (or the wiring from the thermistor)
probably a solid state relay,since the component that does the "heavy lifting" is normally the part that fails

something like this. it will probably read shorted with a meter

updating firmware will not hurt (it also won't help) but you will need to update to latest if you try to talk to any mimaki tech support

 

[Plotter-FIX]

Hey, would be lovely to get a solution for taht spacific machine Thank you nevermind netsol!

 

[netsol]

smoke_jaguar probably has the service manual
lets see if he joins the thread

we have a lot of roland manuals and a few mutoh & gerber

 

[Plotter-FIX]

I have the service manual.... This problem not mentioned... I am a Mimaki technician....

 

[netsol]

Someone needs to measure switched voltage at the switching device. (Solid state relay or triac (?)
does input voltage change although output stays powered?

A TECHNICIAN knows he has to disgnose ALL problems, that occur
NOT JUST the 2% that are listed in troubleshooting section

 

[netsol]

Should be a simple problem.
find switching device.
remove one wire from INPUT
does device turn off? (Does heat stop?)
if yes, change switching device
if no, heck wiring, etc to see what is keeping it turned on

 

[Smoke_Jaguar]

If it is a stuck SSR, it will keep heating until a thermal fuse breaks circuit. Not sure what the cutoff is on those (I mostly do UV, no need for the heaters), but I imagine 50-80C would be in the realm of a safe cutoff. That said, the firmware seems to know what the temp is (assuming it is accurate). Other common causes might be loose sensor (if there is a thermistor on the heater circuit separate from the one that the firmware is using for the display). If I remember right, pre and print should be different zones of the aluminum platen. So, I would expect to see a temperature variation between pre/print of less than 15 degrees, not 30.