Reebok one GT40s treadmill lift motor runs at switch on

[G0RIT]

Good evening I am working on a Reebok oneGT40s treadmill. It had a flashing display which the replacement of D3 rectified. However the lift motor now runs when the mains is turned on and does not stop. If I then select start so the tread motor runs and disconnect the up lead to the lift motor it stops. If I then reconnect the lead the lift motor works as it should with the controls. It will continue to work correctly until the mains is turned off and on again, or the safety device is removed and replaced. It then runs again and only by disconnecting and reconnecting the up lead will it operate correctly. I have tried putting anther motor capacitor in the lead to no avail. Most instructions I can find to reset require turning the mains off which brings the fault back. Any help much appreciated God Bless Allen

[G0RIT]

I should have said disconnect the down lead not the up lead age you know : ) The lift motor is also not under load, as I have the treadmill on its end to work on the motor board so un-coupled its screw from the frame it lifts.

[stj]

does it have limit switches at the end of travel?

[G0RIT]

Thank you for your interest, it has a sensor, but I assume that counts the turns similar to the actuators on a driven satellite dish. I will take a look inside the motor as your suggestion is a thought. It could be trying to reset to zero height at power on ?

[stj]

if it has microswitches with diodes to stop it smashing out of range, check them.
it's handy that you know about sattelite dish jacks - because many of these things are similar
then check any mosfets and relays

[R_J]

If you disconnected the thread end of the actuator, is it just spinning or does it move in or out? The motor likely runs until it sees the down stop position.

[G0RIT]

The thread moves in and out if stopped from turning, it does not have any stops.
The software only allows it to travel so far, that is when it is working correctly as stated below.

I have spent some more time on it today, taking the motor out. It does not have limit switches but relies on the software to limit its travel, which sounds risky, but that is as far as I can tell the way it is. It has a sensor, magnetic with probably a reed type switch, this produces on and off when the motor is running, I metered the lead from it. These pulses are fed into the motor control board.

Pulling that lead out also stopped it running at switch on, but affected the up and down selection in that the up switch would turn into a down switch after a few presses.

I checked the 3,5 mfd 450 volt AC capacitor on the motor for capacitance and leakage, it was fine.

There must be a voltage on the up terminal on the motor board at maims switch on, which disappears if the motor is disconnected then reconnected to it.

The motor is not under load at the moment, but gets very hot with just testing the up and down. The fan at the end can be turned with little effort, could it have shorted turns, could the increased load hold this voltage up at switch on due to the software ?

[R_J]

Have you re assembled the treadmill to see if it will self calibrate? Have you tried the calibration procedure for this model?

[CapLeaker]

I guess these things are known for the incline needing to be recalibrated. Google “Reebok get40s incline calibration”.

[stj]

or sell it and go out for a walk.
i never understand why people buy these mini convayor belts!
https://www.youtube.com/watch?v=Ig4NK2xeboI

[G0RIT]

Originally Posted by R_J

Have you re assembled the treadmill to see if it will self calibrate? Have you tried the calibration procedure for this model?

No it was in two halves when I obtained it on Free Cycle, getting it up the steps into my radio workshop one floor up was fun : )

The only difference to its operation assembled, would be that the motor would be under load, there are no other sensors on the unit other than the one on the lift motor itself, it is however worth a try.

Not easy to do at the moment as I have another older one taking up a lot of space.
I obtained this one as the older one had a belt drive fault which turned out to be in a encapsulated sealed module on the motor board.

I have use a variack to drive that one. : )

[G0RIT]

Originally Posted by CapLeaker

I guess these things are known for the incline needing to be recalibrated. Google “Reebok get40s incline calibration”.

The motor running at start up has thwarted all of the calibration suggestions on line so fat. It does have a calibrate mode button but so far I have been unable to find instructions.

[G0RIT]

Originally Posted by stj

or sell it and go out for a walk.
i never understand why people buy these mini convayor belts!
https://www.youtube.com/watch?v=Ig4NK2xeboI

I run or did until recently three miles a day at 76, but the hills out of Mullion Cove are now a problem which I am trying to over come.

I do not want heart surgery or any other intervention, as our son-in-law died at their hands, the courts have supported this.

I was given the device and find it hard with anything electrical or mechanical not to fix it : )

I expect some of you gentlemen are the same, I would rather have a used device and fix it that buy a new one.

There is also the possibility of modifying a treadmill to use with VR, by mounting it on a rotary platform so that direction of travel can be changed.

It is the interest of doing it and making it all work.

It is difficult with these things as circuits and service data is hard to find, we supply data online for vintage radio etc from the 30s to the 90s but have nothing on these devices.

Thank you all for your suggestions.

Time for a run / walk outside in the sunshine : )

[G0RIT]

I have wired a switch in series with the incline motor so it cannot run at switch on.

After about 3 seconds a relay on the motor board clicks, after that the supply to the lift motor can be restored and all works as it should.

A delay device of some sort is required which I will sort out later.

It could be the relay is slow or some other reason, but difficult to pin it down without a circuit or good knowledge of the workings of this type of circuit.

God Bless G0RIT Allen

[sam_sam_sam]

Dose this device have a troubleshooting screen where you can see if the encoder is counting smooth and not jumping the counting numbers up or down or all over the place

It might not to check encoder is going to be more difficult to do

If does not if you can post a picture of the encoder would help there might be a way to test it

[G0RIT]

Not unless there is some engineering mode I know nothing about. Reebok treadmills have a calibrate mode for speed, but that as far as I know is it.

There is no way that I know or have heard, of connecting into the device, or a trouble shooting mode on its own screen.

[sam_sam_sam]

Some devices have this troubleshooting option and some do not unfortunately

If the encoder has the following pins that ( if it has A / B output pins ) are marked you can still test it’s output but it is not as easily done but it can be done depending on weather or not it analog or if it is digital will make a difference on how you would go about doing the testing ( it should have + / - pins a ground or shield pin and a common pin A / B channel pins now it might only have one channel which perfectly ok depending on the type of encoder it has

[G0RIT]

It is not something I understand Sam, I have been in electronics since 1961 but on the radio repair side.

Stress gets at me now if I delve too deeply into something new, it affects my heart rate.

Too many years in business I guess : )

I do not know where the encoder is, unless it refers to the large chip on the motor board.

I can fix a lot of present day stuff, capacitor faults and so on, but am better with valve equipment : )

Thank you for your interest, I do not fully understand the workings of software or chips., it is a very different world now : )

I have some recent tools such as a heat gun and a power solder extractor, a very useful device.

It even comes in useful with old valve radios, it removes a lot of the solder on wrapped connections, making them easier to un-ravel.

God Bless G0RIT