Grizzly 0704 dead

You can start troubleshooting before you replace the fuse. At this point you probably don't know if the fuse is blowing when you plug the mill in or when you hit the start switch. This will help you figure that out and we can go from there. Otherwise you will be going though a lot of fuses! The side board acts as a filter for the AC power going to the motor control board and looks like it does provide low voltage to the display board. The disc with wire wrapped around it is a torroid used as part of the power line filter. The motor driver board generates a huge amount of electrical noise when it is running, so the filter is used to keep that noise from getting back on the AC mains. Set you meter to the resistance function and set the range to 2K (2000 ohms maximum) connect one lead to the blue wire coming off of the fuse holder. You do not need a fuse installed and the machine should be unplugged. Connect the other lead to the terminal on the side board marked L (it should have teh white wire from the power card connected to it). You should not get a reading - it should indicate open circuit. If you have a reading, let me know what it is. Hold the power switch in the start postion and take another reading - it should drop to around 250 ohms (.25K).
 
If the fuse blows right away this might help.

On thing I've found helpful trying to find a short circuit on automobiles and such, where the fuse blows right away, is to put a bulb in the place of a fuse. This way the bulb lights showing current flowing and it gives you time to find the short. I put the bulb in and start taking things apart. Wiggle connections.

I don't know if this will help here.

Keep working at it! It's probably just a small component on the board that you can get through RadioShack or another supplier.

Glad to hear you got your motor running! That commutator cleaned up nice!
 
Have you looked at the writing diagram in the manual? Bit of a cartoon but it serves the purpose. page 45 http://cdn0.grizzly.com/manuals/g0704_m.pdf

I would check wire for wire to that diagram. Unless something came loose or the previous owner tried to modify the wiring I wouldn't imagine it to be a wiring issue.

Did you try swapping the motor controller yet? SCRs are usually used to control power to the motor and when they fail it isn't uncommon for them to fail in a closed state. This could cause a short. It seems that when you power up the unit the tach lights up and everything is okay until the motor is turned on. If it were me, I would first verify the wiring to the drawing and if that checks out, replace the motor controller.
 
It runs!!!!! Thanks to CodeRage for a used motor and controller board. I finally got it moved from the cold garage to the basement and had time to go thur it. The old controller board was putting about 13 volts to the motor leads. But when motor was hook up it would not run and the voltage dropped to 0. So hooked up the used controller board and then the voltage was up to 64 volts, Hooked up motor and it ran but not much speed. I looked to see where the pots were set on the old board and set the pots on the used board to match and that made the motor run faster and equal in speed forward and reverse, at least by sound. The DRO for the motor speed does not work. Here is what I got

With the forward reverse switch set to neutral and then push in the power switch the display lights up ( not real bright) goes to all number 8's with a decimal and then goes out. When the switch is in forward the display lights, Still dim with all number 8's with decimal. So every part of the display than makes a number or decimal lights. The motor speed knob works but the display never changes from the all dim 8's

So it runs but still has a problem, anyone got an idea what needs to be replaced. I would think maybe the speed sensor but that does not explain why the display is not bright like those I have seen on videos posted on you tube
Like I said it does runs but would like to have everything working that is supposed to

Gary
 
Doubt it is the speed sensor. its just an it transmitter and photo diode. Sounds like the third board might be toast too. What ever took out the motor controller and motor in all likely hood took that sucker out too

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also, very happy to hear that did the trick for yah!

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It seems like it might have gotten struck by a surge, lightening or maybe just a line surge. A lightening surge will wreak havoc on electronics even if it's not a direct hit.
 
In all honesty I feel that utility/lightning surges are over hyped. Lived in Florida for 34 years and I've only had to replace 1 GFCI due to a lightning strike. Don't have any kind of surge protection either. Not saying it doesn't happen but it is very very seldom.

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I would guess that the problem is either a power supply voltage that is too low or the processor on the display is fried. As for surges - here in Kansas I have had numerous answering machines, microwaves, and TV sets blown up by lightning or other surges - finally cured the problem by adding surge suppressors to just about every outlet in the house. I live out in the country on a hill and lightning loves to strike near my house (yes, there are hills in Kansas!).
 
CodeRage said:
In all honesty I feel that utility/lightning surges are over hyped. Lived in Florida for 34 years and I've only had to replace 1 GFCI due to a lightning strike. Don't have any kind of surge protection either. Not saying it doesn't happen but it is very very seldom. Sent from my DROID RAZR using Tapatalk 2
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Do you have an underground service entrance? That makes a huge difference.
 
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