Karrimor Pace treadmill repair E09 error

[Astrodev]

I know this this is probably not of direct interest to quite a few readers but there are a few lessons to be learned as will become clear later.

A while back I got hold of a treadmill branded as a Karrimor Pace model (there may well be other versions similar out there), the problem was that when powered up and the safety key was put in place it would start to go through a self test sequence and within a couple of seconds would show E09 on the display.

So as it was powering up and showing what appeared to be an error message I decided to see what I could find online, but information on this particular treadmill just wasn't giving anything useful, the only thing I did find was for a Roger Black model which looked similar, the .information indicated that the E09 error was due to the running deck not being fully down, So I decided to get the inclination motor assembly out, which turned out to be jammed down, so resetting it to a mid position and putting everything back together and testing it again, resulted in the inclination motor running for a couple of seconds before the error appeared again, this could be repeated until the cam on the potentiometer activated one of the microswitches and stopped the motor (microswitches were wired in series with the motor to act as a limit switch).

At this point I was concluding that the electronics were powering up and that the inclination motor appeared to be working, so I checked the wiring for the pot with a meter and this was fine. Now I looked at the cable between the power and motor control board in the base and the display board in the upper part or the treadmill, because the plug and socket near the top end of this cable assembly was in a bad state, I decided to make up a whole new cable assembly and when this was fitted, guess what, it still gave the E09.

I was now running out of ideas and thought that it could be some information not getting to the display board as based on the markings next to the connector there was VCC, TX, RX GND and SW, from this I concluded that VCC and GND must be OK as the display board was powering up but could the problem be that TX wasn't getting through, as both the TX an RX were going through optoisolators  on the power board I checked the inputs using diode test and seemed to get an open circuit on the TX input, looked like I was getting somewhere so as I did not have any suitable opto's, I ordered a few which arrived 4 days later, this time I had not allowed for the thickness of the conformal coating on the board and although I was applying enough pressure to the probes they can't have been making good contact with the legs on the SMD opto, so even with the opto replaced the error persisted.

Was this time give up or do I give it one last go and assume I know nothing about the fault and this time just go through a check of the main active power components on the board and follow this with a check on the main caps.

The first thing I checked with the meter was a large bridge rectifier (1510) which was reading as shorted across 3 of the pins, I removed it and it was still reading the same, had a look in the parts bin and found a 1560 which I put in and as the other actives a dual diode and an IGBT read OK, I put it all back together and this time it all powered up correctly with no error and everything worked as it should.

There are a few lessons from this repair, firstly don't always rely on the intenet for reliable info, as the initial approach lead me well and truly down the rabbit hole, secondly stick to a methodical fault finding approach, as in this case because things were powering up I ignored things like the bridge rectifier as this must have been working (except in this case it didn't have anything to do with psu part of the circuit) also you would expect a short in a 15A rectifier to cause some obvious faults like blown fuses or tripping something, but in this case it was not even getting warm.

But I must admit I am still kicking myself for not loooking at the problem methodically and completing the repair sooner, at least I can now take out my frustration by running.


Curiously I have seen quite a few of these treadmills for sale with this error code so it makes me wonder if this a common problem, so at least this may help as there is now a post of a possible fix.

[Treadmill Guy]

Thank you for the tip, Some of my skills from a former life came in handy - soldering.

However after completing the exercise I still had the error E09. I dismantled the unit and took it downstairs for the scrap man as I'd used it almost daily for several years. After looking for a suitable replacement I found the nearest to it around 4 times the £260ish I'd paid for it so I dragged it into the garage to have another shot at fixing it, nothing to lose and a grand to be saved. Skills from another former life kicked in as I recall motor vehicle electrics (when one could actually work on them) used to short circuit when you didn't want them to, but also break circuit when one did. I recall having fun with the points in distributers and magnetos. The safety key didn't look like it had any deposits on that might cause it not to make a circuit but I cleaned it anyway. Then with the power obviously off I, very carefully cleaned the contacts at the business end of the safety switch. The unit activated after performing this bit of maintenance. Wish I'd persevered before taking it down stairs as I almost broke my back getting the thing back up. 

[Treadmill Guy]

Or even cleaned the key and contacts BEFORE getting the soldering iron out.