Need help with a failed controller for a treadmill.

[gears47]

The number of cables from the controller to the power board could contain many possible forms of communications.
Having just 5 cables is no indication of what information can be sent, in or out.

Bit confused here...your first photo shows the drive pulley with what appears to be a magnet but you say it contains no magnetism...??

One could say fair enough, maybe just a proximity sensor but most sensors I am aware of (except the reed switch) require 3 cables, yours is just 2.
3 wire sensors usually 5V pos and neg and a signal out.

Reason I am asking is, I have seen videos on some treadmills and they show a pulse from a sensor feeding to the main power board required to ramp up the motor speed.

Have seen also where they simulate this by bridging a couple of input terminals (on and off rapidly) on the power board for on-bench testing.

drive pully: I assumed that it is a magnet, but when I place the reed switch to it nothing happens, yet when I place a magnet to the reed switch it sitches, as shown on multi meter. placed a metal pin to drive pully magnet no grab, when I place a magnet to the drive pully it grabs, so it must be a metal insert and i assume that it has lost its magnetism??

 

[Cirkit]

That's why I suggested rotating the drive pulley manually (in #10) to see if you can register when the magnet passes the reed switch.

 

[Bluejets]

Yes, I said the same in #14.

It may be the magnet is enclosed on the pulley and what you are seeing and showing in the photo could be a counterweight on the opposite side.

 

[gears47]

That's why I suggested rotating the drive pulley manually (in #10) to see if you can register when the magnet passes the reed switch.

I have done that by hand and I do get a change in the reading from .000 to -.000. and sometimes it is .001 when I use the 200dmv range.

 

[Cirkit]

When you tested the sensor removed from the treadmill with another magnet on the bench, you used continuity mode on your multimeter. Can you try using the 200 Ohm range or continuity (beep) mode and testing again.

 

[gears47]

When you tested the sensor removed from the treadmill with another magnet on the bench, you used continuity mode on your multimeter. Can you try using the 200 Ohm range or continuity (beep) mode and testing again.

Re tested with multimeter on 200 ohm range: No magnet = 1 . then with magnet 00.9, 00.8 and 00.7. (pics attached).
I am wondering if this is not a 2 wire solid state speed sensor. I rechecked pully wheel and metal insert has no magnetism.
regards Gears47

 

[Bluejets]

Let's try again shall we..?

With the sensor placed in it's installed position, and a multimeter connected to the two sensor wires on ohms scale, and the pulley rotated by hand, at least one full rotation, does the meter go from open circuit as in photo #2 and #6 above to closed circuit as in #3,4,and 5 photos anywhere in the said full rotation...??

As I said previously, I'm fairly certain the sensor has to be a reed switch as if it were any other type it would require at least 3 wires.

Trying to determine if the lack of pulse from this is the reason behind why the motor is not spooling up.
Never heard of a rare earth magnet loosing it's magnetism except under rather violent poling in a magneto so things not making sense so far.
Tending to think you probably fixed the main fault and need to verify this missing pulse is the reason for no-go. You need to verify this pulse thingo first though.

 

[gears47]

Let's try again shall we..?

With the sensor placed in it's installed position, and a multimeter connected to the two sensor wires on ohms scale, and the pulley rotated by hand, at least one full rotation, does the meter go from open circuit as in photo #2 and #6 above to closed circuit as in #3,4,and 5 photos anywhere in the said full rotation...??

As I said previously, I'm fairly certain the sensor has to be a reed switch as if it were any other type it would require at least 3 wires.

Trying to determine if the lack of pulse from this is the reason behind why the motor is not spooling up.
Never heard of a rare earth magnet loosing it's magnetism except under rather violent poling in a magneto so things not making sense so far.
Tending to think you probably fixed the main fault and need to verify this missing pulse is the reason for no-go. You need to verify this pulse thingo first though.

The meter set on the 200 ohm scale and connected to the sensor shows open circuit after several rotations, even remains open circuit when sensor hard against pully wheel circular inplant. See attached photo.

 

[Bluejets]

Try reconnecting all the wiring connectors including the sensor however just leave the sensor where you can get to it.
With a magnet in hand, fire up the treadmill motor as one would normally while waving the magnet in front of the sensor so that it gives a pulse to the board.

 

[gears47]

Try reconnecting all the wiring connectors including the sensor however just leave the sensor where you can get to it.
With a magnet in hand, fire up the treadmill motor as one would normally while waving the magnet in front of the sensor so that it gives a pulse to the board.

Did that, no change. I must have had a seniors moment the other day! I re checked the pully and found there are two round inserts, 180 degrees apart. 1 is a very strong magnet, the other is not (could be counter weight.) sketch attached. I carried out further checks and found with the 240Vac connected, program selected and start 'On' I had voltage (4.96Vdc) across the 2 pin plug base. Also found that pin 1 & 2 of the 2 pin plug base are connected to pin 2 & pin 5 of the 5 pin plug base respectfully. The 5 pin lead goes to control panel.
Also noticed the LED below the 2 pin plug base illuminated when unit turned on and powered up. The motor still did not run. There must be another faulty component on the controller that I cannot locate. I have ordered a PWM signal generator and awaiting delivery. Thanks for your assistance so far. Regards Gears47.

 

[Bluejets]

The meter set on the 200 ohm scale and connected to the sensor shows open circuit after several rotations, even remains open circuit when sensor hard against pully wheel circular inplant. See attached photo.

then the sensor must be too far away from the magnet. You should get at least one pulse per rev if the details you provided are true.

 

[gears47]

then the sensor must be too far away from the magnet. You should get at least one pulse per rev if the details you provided are true.

Re tested with meter on 200 ohm scale. Meter showed 1 . Rotated motor by hand, one full rotation meter showed 00.0. This was not constant, only got one pulse every so often of rolling motor several times. Sensor about set less than 1mm from pulley.

 

[Bluejets]

Logic concludes you should be getting a solid "ON" in one particular position each and every revolution.
Can you determine where this magnet is in the pulley..??

 

[gears47]

Logic concludes you should be getting a solid "ON" in one particular position each and every revolution.
Can you determine where this magnet is in the pulley..??

In post 30, there is a sketch of the pulley showing where the magnet is located.

 

[Martaine2005]

I think you may need to look into the quantum realm.

Are the possible magnets and or counter weight in the pulley loose?.
Can you remove them?.
Have they or just one possibly fell out and was re-inserted backwards?.

Martin

 

[Bluejets]

In post 30, there is a sketch of the pulley showing where the magnet is located.

As usual, there is a good reason why I asked.
Reason being, if you knew where the magnet was located, then again logic would assume if you placed the sensor right there , then it should work.
As Martaine says, it may be a polarity dependant reed sensor.

 

[gears47]

I think you may need to look into the quantum realm.

Are the possible magnets and or counter weight in the pulley loose?.
Can you remove them?.
Have they or just one possibly fell out and was re-inserted backwards?.

Martin

No, checked both are moulded into pulley, 180 degrees apart. One is a strong magnet, the other show no sign of magnetism.

 

[gears47]

As usual, there is a good reason why I asked.
Reason being, if you knew where the magnet was located, then again logic would assume if you placed the sensor right there , then it should work.
As Martaine says, it may be a polarity dependant reed sensor.

Re tested sensor on 200 ohm scale. Started with magnet there is a circuit, started rotating, open circuit. after one full rotation back at magnet, circuit. If I rotate the pulley quickly can't see any changed in meter reading, possibly my meter isn't sensitive enough to register any circuit. Regards gear47

 

[Bluejets]

Any indication of pulse on the main board perhaps by LED indicator.
You may have to start checking any associated parts around the previously replaced dual diode and mosfet.
Look for high reading on any adjacent resistors or any signs of crapped out caps(bulged on top or leaking).

 

[gears47]

Any indication of pulse on the main board perhaps by LED indicator.
You may have to start checking any associated parts around the previously replaced dual diode and mosfet.
Look for high reading on any adjacent resistors or any signs of crapped out caps(bulged on top or leaking).

Thanks, I will do that and get back to you if I find anything, regards gears47