How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Russell H. Your Own Question
Russell H.
Russell H., Service Tech
Category: Exercise Equipment
Satisfied Customers: 10924
Experience:  8+ years of professional experience
Type Your Exercise Equipment Question Here...
Russell H. is online now
A new question is answered every 9 seconds

Treadmill only runs on max speed

Customer Question

treadmill only runs on max speed
Submitted: 1 year ago.
Category: Exercise Equipment
Expert:  Russell H. replied 1 year ago.
Hi, thank you for contacting My name is Russell. I will do my best to provide the right answer to your question. That sounds like either a defective or 'jammed up' control console... or, a defective motor controller board. To eliminate the console (if that's not it) try a reset of the machine, or a reset of the console, or a speed calibration operation.(What is the maker and model of your treadmill, please?) Usually if the speed sensor is disabled, then it is sensed and the treadmill shuts down. So I suspect that the speed sensor is OK but the motor controller board (that goes with the belt motor) is not OK
Customer: replied 1 year ago.
this a livestrong LS7.9T. I was on the treadmill walking and all of a sudden it made bang noise and then it started to run at max speed. I almost fell off the machine. This machine is about 7 years old, and has clocked in lots of miles. What scares me is that the default should be that it should stop rather than going at a max speed - why did this happen? I don't know about treadmills, so you will have to walk me through the process.
Expert:  Russell H. replied 1 year ago.
That sounds very alarming and quite dangerous.A 'bang' implies that circuitry exploded. If so, that should be very easy to spot, once you get the outer case pieces of the machine Off. But first: How old is the treadmill, measured from purchase date? if it is new enough, don't try removing the outer case at all, that would void the warranty.
Customer: replied 1 year ago.
as stated, it is about 7 years old and was used quite often - i want to say, average 2-3 miles 5 days a week. It will be good, if you can lay out the whole thing in one email so we reduce the down-time. And since it is 7 plus years old - there are NO warranties on the machine.
Expert:  Russell H. replied 1 year ago.
Unfortunately I'm not knowledgeable about how to take the cover pieces off this model.Let's say you start with the side rails, on either side of the walking platform. That's fairly usual.But what diagrams I have don't indicate where the fasteners for those side rails are, just that they do come off for certain, and that most of the significant parts (that might have gone bang) are under the front of the walking platform.If you turn the treadmill on its side, you may see screws or fasteners on the underside that allow a plate, under the front end of the walking platform, to be removed. But the diagrams aren't very clear on that point, I'm sorry to say.
Customer: replied 1 year ago.
I am trying to attach the image but it says file size too big. Is there any other email or phone number where i can text it?
Expert:  Russell H. replied 1 year ago.
You can use the Paint program to reduce an image that is too large, by using the Resize function of that program after loading the image file, then Resizing it, then saving that resized version.
Customer: replied 1 year ago.
see the image.
Expert:  Russell H. replied 1 year ago.
Inspect the circuit boards to the right in that picture. Anything burnt out? or a blown fuse perhaps?
Customer: replied 1 year ago.
from outside, nothing looks out of place. they look fine.
Expert:  Russell H. replied 1 year ago.
Well, where did the 'bang' come from, then? such a noise is not made by 'nothing'.How about drive belts, etc.? how does the walking belt look, is it frayed, or cracked, anywhere? if you can turn the treadmill on very slow - if that's still possible - and without actually stepping on it - you could examine the walking belt that way.
Customer: replied 1 year ago.
Russell - If there is only one bang and if you are walking on the treadmill with TV on it is hard to make out where it came from. When you plug it back on in the same electrical socket, it starts to run at maximum speed, so clearly the bang is not from the socket - so socket is fine. The machine runs at 12 miles an hour - so motor is fine and so is the belt. Those things can be very easily eliminated. The common sense approach says, that it must have a speed calibrator/sensor which regulates the speed. There is a good possibility that a fuse or such speed sensor has gone bad. I just don't where that piece sits and how to check if that piece has gone bad. If you do not know much about this particular brand - then it could be difficult for you tell me where to look. It is for this reason, I said, you can call me at(###) ###-####and I can walk you through, when I am at home.
Expert:  Russell H. replied 1 year ago.
Thanks for your understanding attitude.I admit that even with diagrams available, I barely was able to offer some help with getting it disassembled.The speed sensor does need to be checked, yes.It (the sensor) usually is located next to a rotating part of the running belt drive and belt motor. When a portion of the rotating part of the running belt drive passes the sensor, the sensor 'reads' the rotating part, and the circuitry counts up the reads per second, and calculates the belt speed from that.Usually if the speed sensor does not register properly, the treadmill STOPS, period. For safety reasons, that is how it is designed. So... my guess is that your treadmill has a speed sensor that is barely at the edge of working, and has few 'reads' per rotation, making the circuitry think it is running slower than it is.But: that 'bang'... it doesn't bode well for any part. And I still say that even if something is found wrong with the speed sensor, you still should replace the motor controller board. For safety reasons, simply. Where is the sensor? your photographs unfortunately, though good, did not show me where it is located. Reading the diagrams available to me for this model.......I find that it is listed as P06, Catalog Number: 49003636 and it is shown as attached to the frame of the running bed of the treadmill, as you stand on the treadmill, it is on the forward left side of the frame, more or less, according to the diagrams I have. It is a magnetic sensor, which senses a magnet passing near it on the moving / rotating parts of the treadmill as it works.