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QT 18 no start

simonswb6

Aluminum
Joined
Feb 11, 2013
Location
ny
I have a 1994 mazak qt18 with a tplus control. I went to start it today and nothing happens. i hear the fans turn on when you turn the main switch on. However, when the Green start button is pressed, nothing happens. (the green button is illuminated) I had someone push the green start button while i was in the back electrical cabinet and i hear something clicking in the MITSUBISHI NC Power Supply QX084 and a red led flashes ( red circle in picture) . I have replaced the 2 - 24v power supplies shown in a blue circle and just checked and they appear ok. Does anyone know if i should focus on the NC power supply? anything to check w/ the meter?

on a normal startup i hear the main breaker trip, then the hydrualic pump.


ps.JPG
 
I have a 1994 mazak qt18 with a tplus control. I went to start it today and nothing happens. i hear the fans turn on when you turn the main switch on. However, when the Green start button is pressed, nothing happens. (the green button is illuminated) I had someone push the green start button while i was in the back electrical cabinet and i hear something clicking in the MITSUBISHI NC Power Supply QX084 and a red led flashes ( red circle in picture) . I have replaced the 2 - 24v power supplies shown in a blue circle and just checked and they appear ok. Does anyone know if i should focus on the NC power supply? anything to check w/ the meter?

on a normal startup i hear the main breaker trip, then the hydrualic pump.


View attachment 266639

update
i pulled the nc power supply, notice the 2 caps that bled and burned out the other components... im not sure if this is the only problem but maybe part of the problem.

bled.jpg
20191006_062558.jpg
 
update
i pulled the nc power supply, notice the 2 caps that bled and burned out the other components... im not sure if this is the only problem but maybe part of the problem.

View attachment 266690
View attachment 266692
Replace capacitors, the same goes for burned components (I see a diode and two small SMT capacitors near electrolytic caps- change these too, as electrolyte leakage do a damage both to components and PCB traces). Also suggest to check voltage stabilizer ICs (mounted on heatsink)on that line where bad caps are located. These components aren't expensive.
 
Yes, the power supply is the most-common failure point of the T/M-Plus NC control unit.

Check Ebay for good prices on a spare....
 
The backup battery for the programs and parameters etc is on the P.S.
If it is unplugged overnight, you probably will need to re-initialize the control, and replace the items lost.

Bill
 








 
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