[Neverliftchassi]

I've had this mill for a year and a week so well its out of warranty. I was running the mill for a few hours straight on Sat. nothing too heavy max was about .050 cut and the power kicked off on the machine. I attempted to start the unit back up and nothing so i left it unplugged and tried to start it up the next day the mill still wont power on. I have checked both fuses and verified that I'm getting power to and through the switch along with 110 at all the connections in the wiring diagram that shows. but the tach wont power up and nothing happens. I have read about people having motor problems but nothing turns on I would assume that if it was the motor at least i would be able to get the display to turn on. Is there a way to test the motor itself to see if its control boards or the motor.

[john-100]

having a quick look at the diagram on page 45

http://cdn0.grizzly.com/manuals/g0704_m.pdf

G0704 Wiring Diagram.pdf

with no display on the tachometer

I would have a look at the Guard Limit Switch

the switch could be faulty or not being closed when the guard is in position

the switch is connected to PCB CESX 1101-28 that will be the DC power supply and interface for the tacho module

PCB CESX 1101-28 will also be part of the interlock that ensures you start the spindle with the spindle guard in place

photo found on the net


John

PS

does the no volt release on/off switch latch on

[Neverliftchassi]

having a quick look at the diagram on page 45

http://cdn0.grizzly.com/manuals/g0704_m.pdf

G0704 Wiring Diagram.pdf

with no display on the tachometer

I would have a look at the Guard Limit Switch

the switch could be faulty or not being closed when the guard is in position

the switch is connected to PCB CESX 1101-28 that will be the DC power supply and interface for the tacho module

PCB CESX 1101-28 will also be part of the interlock that ensures you start the spindle with the spindle guard in place

photo found on the net


John

PS

does the no volt release on/off switch latch on

It will probably be friday before I get a chance to look at that. I am not really sure what you are saying in the PS. I did notice that when i was in the case some of the nuts had vibrated loose and were sitting in the case.

[john-100]

if the machines on/off switch is the type I think it is
Attachment 400998

when terminals A1 & 24 are connected together
the switch will remain on when the green button is pressed
the coil is energised and will hold the switch on (latch on)

when the connection between A1 & 24 is broken the coil is no longer powered and the switch will open

Attachment 400996
note - this is the 240V version of the switch

--------------------------


looking at the photo of the JS239508253GB

this is what I see

Attachment 400956



1) a mains filter ,
mains filter circuit
Attachment 401024


2) a step down transformer , bridge rectifier & capacitor and 5V regulator IC
making a simple linear power supply to power the tachometer module


I expect the power supply & connections to the tachometer module
will be like this
Attachment 401026

a detailed photos of the both sides of the board
will help to reverse engineer the board to create a circuit diagram / schematic

the odd thing following the wiring diagram the live supply passis through a 15A fuse that is connected to the "N in " as marked on the CESX 1101-28 PCB !!!!!
the neutral going to the "L in "

more of an issue is the guard switch breaking the neutral to the on off switch



looking at how the no volt release switch is wired

when a spindle direction is selected
terminals 9& 10 are closed connecting A1 & 24 on the on/off switch
this powers the solenoid in the on/off switch and enables it to latch on when the green button is pushed

switching the spindle direction to off , pressing the red stop button or opening of the guard switch
will cause the on /off button to switch off


A break in the wiring between terminal 24 on the on/off switch and the transformer
would cause the loss of power to the tachometer


John

[Neverliftchassi]

if the machines on/off switch is the type I think it is


when terminals A1 & 24 are connected together
the switch will remain on when the green button is pressed
the coil is energised and will hold the switch on (latch on)

when the connection between A1 & 24 is broken the coil is no longer powered and the switch will open


note - this is the 240V version of the switch

--------------------------


looking at the photo of the JS239508253GB

this is what I see





1) a mains filter ,
mains filter circuit



2) a step down transformer , bridge rectifier & capacitor and 5V regulator IC
making a simple linear power supply to power the tachometer module


I expect the power supply & connections to the tachometer module
will be like this


a detailed photos of the both sides of the board
will help to reverse engineer the board to create a circuit diagram / schematic

the odd thing following the wiring diagram the live supply passis through a 15A fuse that is connected to the "N in " as marked on the CESX 1101-28 PCB !!!!!
the neutral going to the "L in "

more of an issue is the guard switch breaking the neutral to the on off switch



looking at how the no volt release switch is wired

when a spindle direction is selected
terminals 9& 10 are closed connecting A1 & 24 on the on/off switch
this powers the solenoid in the on/off switch and enables it to latch on when the green button is pushed

switching the spindle direction to off , pressing the red stop button or opening of the guard switch
will cause the on /off button to switch off


A break in the wiring between terminal 24 on the on/off switch and the transformer
would cause the loss of power to the tachometer


John

John I had one of the guys stop and check the switch to see if it would latch on it didn't appear to. I will be up there tomorrow afternoon to look at it some more.

-Kyle

[Neverliftchassi]

I just want to thank everyone I pulled the switch and started probing the wires leading to the switch and all appeared to work bypassed the chip guard safety switch unit powers up and operates normally now if i could just get the rpm to read again its been straight 0000000 for the last few months.

[john-100]

if the tacho sensor on the G0704 is like the sensor on other lathes I have looked at

the 3 core cable is soldered to the sensor PCB and can easily break and

if the board moves its possible for the slotted disk to damage the optical sensor


sensor
Attachment 402094



sensor PCB



sensor cable
Attachment 402092


John

[JeffAvery]

if the tacho sensor on the G0704 is like the sensor on other lathes I have looked at

the 3 core cable is soldered to the sensor PCB and can easily break and

if the board moves its possible for the slotted disk to damage the optical sensor


sensor
Attachment 402094



sensor PCB



sensor cable
Attachment 402092


John

I just signed up today so I could say thank you for this post. I was having some trouble getting a new to me (used) G0704 to power up and this walked me right through it. I really appreciate it. Best, Jeff