mastercraft 2.5a corded oscillating not power on

Thread Starter

LAOADAM

Joined Nov 21, 2018
862

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ThePanMan

Joined Mar 13, 2020
773
The control board is potted, so chances are there are no (quote: user serviceable parts).

An overall picture would be useful. Both C & D are black wires, which suggests they may be common to one and other. I see a red wire as well. Do you get any voltage between the red and one or the other black wires?
 

Thread Starter

LAOADAM

Joined Nov 21, 2018
862
The control board is potted, so chances are there are no (quote: user serviceable parts).

An overall picture would be useful. Both C & D are black wires, which suggests they may be common to one and other. I see a red wire as well. Do you get any voltage between the red and one or the other black wires?
Thanks.
there are just 4 wires. there other 2 blacks for switch; and other 3 colour wires for speed adjuest pot.
all other wires breach out from C/D for brushes etc.
 

MaxHeadRoom

Joined Jul 18, 2013
28,617
Bit late for this one, but a future alternative is Princess Auto, (No Sale is Final Until You are Satisfied). :cool:
They have always honored it for me!. ;)
 

MisterBill2

Joined Jan 23, 2018
18,175
REally, the module would be repairable if it had not been encapsulated to make it non-repairable. If it is supposed to be providing 24 volts DC for the motor, the service procedure will be to measure the motor voltage. The other possible problem could be the variable speed control. That can be checked with the power feed disconnected.
 

MaxHeadRoom

Joined Jul 18, 2013
28,617
No doubt uses a Universal (AC/DC) motor.
If that is a 120v Triac controller, then it would be simple to replace it, with test running the motor on 24vd and it runs slow, the motor is probably OK.
 

MisterBill2

Joined Jan 23, 2018
18,175
Once again, the one part that could be checked and replaced is the external speed control variable resistor. So that needs to be checked using an ohm meter, with the device disconnected from the mains.
Then also, if that circuit board is coated with tar, it can be cleaned off and repaired fairly easily. A tar coating would be black and able to be melted, or removed with a common solvent, even gasoline. Certainly that requires a great deal of caution and should only be done by one familiar with the needed precautions.
But it seems that the TS mentioned brushes. So the motor may be either a universal type, or more likely a permanent magnet DC motor. For that determination we need more information.
If the TS has a multimeter then a great deal can be learned, if not, then only guesses will be made.
 

MaxHeadRoom

Joined Jul 18, 2013
28,617
Personally I would see if the power IC showing can be removed, appears to be a Triac?
If defective,, might even be possible to replace it by cleaning the leads coming out of the potting. ;)
Also the three speed control leads appear to exit at the bottom of the enclosure.
 
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MisterBill2

Joined Jan 23, 2018
18,175
Consider that a damaged or failed speed control could be the cause of the inability to run at a higher seed, testing that control seems very much a good choice the. And if the material covering the PCB is a tar type of material then it can be removed so that other components could be replaced.
 

MaxHeadRoom

Joined Jul 18, 2013
28,617
Consider that a damaged or failed speed control could be the cause of the inability to run at a higher seed, testing that control seems very much a good choice the.
The way I read it, the running at slow speed was due to the OP using 24vdc on the motor leads to test, if so obviously that will be the result!?
"Oscillating Multi-Tool"
 

MisterBill2

Joined Jan 23, 2018
18,175
The way I read it, the running at slow speed was due to the OP using 24vdc on the motor leads to test, if so obviously that will be the result!?
"Oscillating Multi-Tool"
The fact that the motor does run at 24volts DC does tell me that probably the motor is OK.
Otherwise, one option worth considering would be to bypass the module completely, wire the switch in line with the power cord directly to the motor, and use an external speed controller. like those available for controlling drill motors.
 

MaxHeadRoom

Joined Jul 18, 2013
28,617
As per #8, if the semi can be removed and identifies, should be easy to replace if that is the problem, also clarify if Triac control.
I imagine they would use mechanical reversing for the oscillations.
 

Thread Starter

LAOADAM

Joined Nov 21, 2018
862
Once again, the one part that could be checked and replaced is the external speed control variable resistor. So that needs to be checked using an ohm meter, with the device disconnected from the mains.
Then also, if that circuit board is coated with tar, it can be cleaned off and repaired fairly easily. A tar coating would be black and able to be melted, or removed with a common solvent, even gasoline. Certainly that requires a great deal of caution and should only be done by one familiar with the needed precautions.
But it seems that the TS mentioned brushes. So the motor may be either a universal type, or more likely a permanent magnet DC motor. For that determination we need more information.
If the TS has a multimeter then a great deal can be learned, if not, then only guesses will be made.
Thanks.
sure I have a multimeter. just don't know what to do to measure?
BTW. I bought another. so this one can do any thing on it, even tear it down.
 

Thread Starter

LAOADAM

Joined Nov 21, 2018
862
Personally I would see if the power IC showing can be removed, appears to be a Triac?
If defective,, might even be possible to replace it by cleaning the leads coming out of the potting. ;)
Also the three speed control leads appear to exit at the bottom of the enclosure.
good. I'll try from here.
 

Thread Starter

LAOADAM

Joined Nov 21, 2018
862
Consider that a damaged or failed speed control could be the cause of the inability to run at a higher seed, testing that control seems very much a good choice the. And if the material covering the PCB is a tar type of material then it can be removed so that other components could be replaced.
I'll check it.
 
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