I couldn't find the old thread about this so started a new one.
My 86 YO neighbor thinks I'm an electronic wizard who can fix anything and I do not discourage him, but recently my reputation got tested when his electric mobility scooter/chair refused to run... It got caught outdoors during a serious 1-1/2" rain storm and apparently the moisture led to the fault.
The embedded controller had smart diagnostics and was beeping out that the problem was with the speed control and/or wig-wag pot. (They call the forward/back lever control the wig-wag pot.). When the unit powers up it checks that the wig-wag pot is centered, and if not won't run.
After much digging into the wiring harness looking for the problem, I traced the wig-wag wiring all the way back to the embedded processor and confirmed continuity.
Inside the sealed(?) control box where the processor and control electronics I could see evidence of previous water damage, but it did not look recent or wet. When I removed the processor PCB and flipped it over, I could see some smutz (technical term) on the PCB in the area with a bunch of small SMD resistor.
I grabbed a q-tip and some rubbing alcohol to clean off the PCB and the fault cleared. So literally zero parts cost to repair. Of course then I had to repair the stuff I broke taking it apart. There was an old ribbon cable on the battery voltage meter with several broken wires I had to re-solder.
Apparently there is a max speed limit pot inside that limits the top speed of the scooter for safety reasons. I think they adjust it for 4 mph... I decided to turn that full up, so now my neighbors scooter moves a lot more briskly. 8)
So the lesson is the combination of rainwater and dirt or old corrosion can leave behind a conductive enough residue to mess with the embedded controller. It could have been worse, the fault just interfered with an external input, and not the high power control stuff.
JR
PS: I am a little reluctant to admit this but I am generally impressed by the design. Apparently there are about 20 similar models with the same guts made by one company in China. The built in trouble shooting beep codes probably help most service repairs,,, In my case it led me to waste a bunch of time on the controls when the problem was inside the control box, but alls well that ends well.
My 86 YO neighbor thinks I'm an electronic wizard who can fix anything and I do not discourage him, but recently my reputation got tested when his electric mobility scooter/chair refused to run... It got caught outdoors during a serious 1-1/2" rain storm and apparently the moisture led to the fault.
The embedded controller had smart diagnostics and was beeping out that the problem was with the speed control and/or wig-wag pot. (They call the forward/back lever control the wig-wag pot.). When the unit powers up it checks that the wig-wag pot is centered, and if not won't run.
After much digging into the wiring harness looking for the problem, I traced the wig-wag wiring all the way back to the embedded processor and confirmed continuity.
Inside the sealed(?) control box where the processor and control electronics I could see evidence of previous water damage, but it did not look recent or wet. When I removed the processor PCB and flipped it over, I could see some smutz (technical term) on the PCB in the area with a bunch of small SMD resistor.
I grabbed a q-tip and some rubbing alcohol to clean off the PCB and the fault cleared. So literally zero parts cost to repair. Of course then I had to repair the stuff I broke taking it apart. There was an old ribbon cable on the battery voltage meter with several broken wires I had to re-solder.
Apparently there is a max speed limit pot inside that limits the top speed of the scooter for safety reasons. I think they adjust it for 4 mph... I decided to turn that full up, so now my neighbors scooter moves a lot more briskly. 8)
So the lesson is the combination of rainwater and dirt or old corrosion can leave behind a conductive enough residue to mess with the embedded controller. It could have been worse, the fault just interfered with an external input, and not the high power control stuff.
JR
PS: I am a little reluctant to admit this but I am generally impressed by the design. Apparently there are about 20 similar models with the same guts made by one company in China. The built in trouble shooting beep codes probably help most service repairs,,, In my case it led me to waste a bunch of time on the controls when the problem was inside the control box, but alls well that ends well.
