Grizzly 0704 dead

[Gman45acp]

I took the motor off and removed both brushes, They are not the same, They are slightly different size and the one with the clamp on it the wire is twisted and almost disconnected. The one has a deformed spring and the metal cap on the end is missing two legs that slide into where the brush fits in the motor. I and going to remove the gear on the end of the shaft and disassemble the motor to see if I can see and internal damage, If not will order a set do brushes and caps



There should be a second picture of the motor which has two black spot on the housing, look like burns, Wonder how they got there
There was not voltage to the motor lead so I am guessing the board is also bad. I think the first thing to do if is see nothing fried inside the motor would be to get the brushes and caps and then see if motor will run hooked direct to 12vdc

gary

 

[DAN_IN_MN]

Gary

Looks like you may be on to something here.

Why is the paper clip/clamp in this pic?



I'd pull the motor apart and check out the commutator.

 

[Gman45acp]

The clip is use to hold the spring back so it shows the frayed and twisted wire going to the bruch

Gary

 

[iron man]

View attachment 65033View attachment 65034I took the motor off and removed both brushes, They are not the same, They are slightly different size and the one with the clamp on it the wire is twisted and almost disconnected. The one has a deformed spring and the metal cap on the end is missing two legs that slide into where the brush fits in the motor. I and going to remove the gear on the end of the shaft and disassemble the motor to see if I can see and internal damage, If not will order a set do brushes and caps



There should be a second picture of the motor which has two black spot on the housing, look like burns, Wonder how they got there
There was not voltage to the motor lead so I am guessing the board is also bad. I think the first thing to do if is see nothing fried inside the motor would be to get the brushes and caps and then see if motor will run hooked direct to 12vdc

gary

I would really look around and see what was arcing on the motor with all the brush as bad as they are the armature may not be any better. It may have taken out the board. It could be that the brushes where grounding out and energizing the housing and it started to arc against the case too bad... Ray

 

[DAN_IN_MN]

The clip is use to hold the spring back so it shows the frayed and twisted wire going to the bruch

Gary

Oh, Good idea!

Another thing that would concern me would be the power strain relief that looks like it's coming out of the motor! Are the wires shorting out inside? I'd take the motor apart.

 

[SEK_22Hornet]

I did a little looking at my G0704 and here are some things you can check. On the AC power side, the voltage comes in to the little board with the transformer on it to terminals toward the bottom of the board (the power cord black and white wires). I clipped the ground of my meter to the AC ground at the outlet I was plugged into and traced the power through the chip guard switch (blue and brown wires in a cable). The AC is cut off to the brown wire whenever the chip guard is swung out of position. Measuring at the power switch, I found that both the common and the hot wires go through the switch. The switch is a magnetic locking switch. A fifth terminal with a white wire to it provides 110 volts to hold the switch in, through the barrel switch. Black wires carry the power to the L1 and L2 terminals on the motor driver board, which does look like the one already posted.

A couple things to check - Make sure you have the barrel switch (direction) in forward position. When you hold the power switch in, does the red LED Tach light up? does it stay lit when you release the switch? If these are both yes, can you hear the power switch click when you unplug the power?

Measuring the output of the driver board can be difficult with most digital meters. To check it out, try wiring an outlet or cut off extension cord in place of the motor and plugging a regular light bulb into it and see if it will light up. See if you can vary the brightness of the bulb with the speed control. Check forward and reverse to make sure the barrel switch is OK.

The motor measured 4 ohms when I checked the resistance across the two wires.

The black on the motor may not be from arcing - if he used electrical tape to hold the broken cap on, it could just be adhesive residue.

 

[Gman45acp]

Wires are attached in side the motor, Motor is apart, can't see ant thing suspicious all the windings look goof. Will post picture later tonight

 

[davidh]

if you see the brush springs have gotten hot, are loose and collapsed, the brushes need to be replaced. it appears that they are shot.
without the proper brush holder cap, the brush will not be able to make a good contact with the armature, the pressure that the spring produces will be un acceptable and it will heat up more and get destroyed.
order a set of brushes for it and the proper cap.
the motor problem may have developed from the board being a problem and im clueless about electronics, just a bit knowlegable about small motors as I use to repair them for a living for many years. .
sorry, I can't spell any longer.
davidh

 

[Gman45acp]

Here is picture of the armature. Every tab has wire attached and I can't see any burnt wires. I have a motor and control board coming from another forum member. Once machine is operating( if those part fix it). Then I can remove brushes from the working motor and see if it then will run
if it does then get a new set and will have a spare motor

 

[xalky]

The motor looks good to me. I think those brushes gotta go for sure. If there's a motor repair place nearby, they might have those brushes and caps in stock. The brushes might have been the problem all along.