CT 36 (2011) Loss od power. Control board shows 34 volts going to Turbine.

[KentonIwao]

Hi. Vac failed to run. Disassembly showed brushes are short but still have carbon left. Bench tested turbine and it fires up.

Bench tested control board: In Auto I get 120 volt to the aux. plug. In Manual and Auto I get 34 volt to the turbine.

Does anyone know the voltage specs for the control board? Or any advice on trouble shooting power to the turbine.

The stator(field winding) assembly seems to be slightly loose have a little play/rattle.
Thanks for any advice

 

[AlexThePalex]

Well, 34 volts to the motor sheems a bit shy of what it should be.

Sounds like there is a faulty component on the electronics board. You can only order the board as a whole, so unless you're a electronics enthousiast who can measure every component on the board, the easiest way to go is to the order the entire board anew.

 

[squall_line]

Depending on the time and cost of brushes, if they're short, it might be worth replacing them first, even if they look like "they still have carbon left".

 

[afish]

I agree with squall line.  I have had brushes that looked ok to iffy and I replaced them and it fixed my issue.  For the few dollars that's step one. This does depend on the machine age, amount of use/ abuse etc.  If its older and gets plenty of use then might as well replace the brushes anyway. Now if its newer, light use or took a tumble then its probably something else.   

 

[AlexThePalex]

Festool brushes have a little spring inside that activates when the brush is too worn down. The brush is fully functional until the spring jumps out. If you don't see the spring sticking out, your brush is not the problem.

 

[KentonIwao]

I ordered a new motor (turbine) and the ct36 works like its brand new.

 

[imdking]

I ordered a new motor (turbine) and the ct36 works like its brand new.

Great! Glad you were able to get it going again.
What led you to believe the turbine needed to be replaced?

Thank you for coming back and announcing that the machine has been fixed, instead of leaving the thread without a solution. We appreciate that, and it will help those searching with similar problems in the future.

 

[KentonIwao]

After disassembly. There was no apparent damage to the control board. I was not sure exactly what to measure, but I was getting power to the aux plug and 75 volts to the turbine.

I bench tested the turbine and it spun up, but there was a rattle caused by the field winding being loose. You could move it up and down inside the hosing 2mm or so. The brushes were nearing the end of life. The machine has been used almost daily for ten years, so I figured that it was due a new turbine/motor.

The replacement brushes from festool are $50. The new turbine which comes with new brushes(installed) and even new gaskets was $130 with shipping and tax.

There is nothing else inside the vac to wear out so it seems totally worth it considering it was purchased in 2011.

Works perfect now, is quieter, smoother and plenty of suction.

Only downside is the part took 10 days to arrive.

 

[imdking]

Good call. It makes sense to go with the assembly and not just the brushes.

Enjoy another 10 years.