How to replace carbon brushes - Sewing Machines

The motor needs to be serviced , perhaps the brushes are sticking in their slides.

Are you saying the foot controller has carbon brushes? If so, the carbon brushes are probably worn down so they are no longer making contact. You can try looking for replacement carbon brushes.

Most likely your machine has carbon brushes that are worn and need to be replaced. (intermittent start-stop is a strong indicator. Not sure on your 801, but a lot of the older Berninas have carbon brushes in the motor (I've replaced them on an 830), Newer models have them in the foot control. Once you locate them, you can order replacements for probably less than $20 and your machine will run like a champ! There are web sites and videos that have instructions.

sewing machine carbon Google Search

Hm, I'm wondering if the carbon brushes in the foot control unit are worn. I have a 930 Record that started running unevenly. We took the foot control unit apart and replaced the two carbon brushes for about $25 and the sewing machine is still running fine today.

If your machine is an older mechanical machine, most likely it is seizing due to old oil that has dried out and locking the moving parts. If this is the case with your machine, AVOID using your machine until the problem is addressed or the motor could be damaged with further use.

Wheel on right side that controls the needle up and down is very tight...

The other thing to check are the carbon brushes. There may be some in the motor and/or the foot control unit. Over time, these carbon brushes will wear down until they no longer make the appropriate connection. If you are mechanical, you can usually order replacement brushes for your machine for ~$15 and replace them yourself. Be sure to confirm the brushes your order are for your make/model machine.

Amazon com Generic Sewing Machine Motor Carbon Brushes CMB7 Everything Else

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In the following parts list, on page 13, it shows item #5 as carbon brushes in the motor. Carbon brushes would normally be in the motor or perhaps, the foot control, but there don't appear to be any in the foot control unit.

Here's a parts list for your machine:

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0ahUKEwi5zs-FxoLUAhXrz1QKHUD8DDUQFggmMAA&url=http%3A%2F%2Fwww.raichert.com%2Fadobe%2FMO654%2FM654DE%2520Parts%2520List.pdf&usg=AFQjCNE2xWhzI2cqCKXL3jcLzhj89BjxPQ&cad=rja

Some of these old machines have carbon brushes in them. When it gets worn down from use and eventually fails to make contact, it will no longer work. The replacement carbon brush is relatively inexpensive ~$15.

It could very well be the carbon brush. It is generally a piece of soft carbon (like pencil lead) with a spring on the end which applies pressure. When the carbon gets worn down, it does not make consistent contact. Depends on your machine model. I've replaced carbon brushes on the motor of an 830 Record, but I had to replace something in the foot control. Do not despair. The replacements can be found for ~ $12-15. Available multiple places. Just be sure they will fit your machine.

2 Bernina Carbon Brushes for All New Style Machines eBay

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THE MOTOR USUALLY HAS A LARGE SCREW. WHEN YOU REMOVE THE SCREW THE CARBON BRUSHES WILL SHOW. THERE IS USUALLY TWO. YOU CAN TAKE THEM TO A LOCAL MOTOR SHOP TO GET NEW ONES.

well particular on electrical problem foot control is a switch of motor that deliver speed varies on how you press the foot pedal it consist of circular thick plate carbon the old model and the new one electronically control of power ic,It depend on how this pedal was contro.Anyway besure the power is off or unplug the machine; this control was been connected in series connection to the motor which you can test if your foot pedal control is defective. Disconnect the line wire holding foot pedal from the terminal inside motor assembly.If your not qualified electrician don.t do this.Connect the two terminal wire that inside the machine where the motor mounted.This connection is supplying your motor in full speed,Declucth your machine from the handwheel so that the motor run only.Plug the machine and switcn but you must jug only if the motor run in couple second of course without the foot control this was disconnected already.So your foot control is defective vice versa if motor does not run without foot control motor is busted.
how to fix if foot contol is defective, in carbon type you must replcace the circular thick carbon.On Electronic control check the IC if this open or some capacitor and resistor are open,Replaced any pars that had been short circuited.If the motor is defective replaced the carbon brush mounted at two side of motor case,There is an opening port.The carbon brush has spring holding push this carbon brush to the brush armature of rotor.