C500 standing actuator maybe

[jefferso]

My old C500s has a new problem. It still stands, but with a lot of creaking and some slightly odd movements. Once it's standing it will move (slowly, with turtle showing). When I go down from standing, about 20% the way down, the 2nd light on the ICS turns red. It goes most of the way down, but then only shows the backrest and M1 on the joystick, none of the other normal functions such as tilt, elevate, footrest. The control then has the blinking turtle and won't move. It's still elevated a fair amount so won't go under my desk, so not useful for working.

The standing actuator is now unplugged, and the chair can move, but the other functions still don't work, and of course it won't stand again since that actuator is unplugged. I tried unplugging, giving a spray of deoxit, waiting a bit, plugging back in, but it didn't change.

I tried doing an ICS autocalibrate but it doesn't seem to work. After holding buttons 3, 5, 6 and turning on, it doesn't turn green, but then when the light on the right is red, pressing button 4 doesn't do anything.

I wonder if some microswitch or actuator sensor is being activated when it goes down beyond a certain point. Then it won't move and won't let any function except M1 and recline work.

[Burgerman]

Would love to advise but I cant. Its some permobil secret magic thing. Maybe Rover can. He worked for permobil and is logged in right now!

[swalker]

Years ago I had very similar symptoms on my C500 VS wheelchair.

The technician at the shop diagnosed it as a microswitch that was not making contact when it should have. They said this was a very common problem. They simply shimmed the microswitch so it made contact properly and the wheelchair has worked fine ever since (I used the standing feature within the last week and it still works fine).

I am not sure which microswitch it was.

One observation is that the emergency "take me down" procedure worked fine to put the chair in a normally seated position.

That procedure is explained on page 78 of the Permobil ICS Onboard Configuration document. The document is too large to attach. You can download it from this link: https://www.manualslib.com/download/147 ... l-Ics.html

Steve

[jefferso]

Thanks. I couldn't find a microswitch other than the main one in the middle under the seat under the big plastic plate (which was removed long ago due to the switch being activated when it shouldn't).

The chair will drive now when one of the plugs to the standing actuator is unplugged (with red, white and blue wires), but of course it won't change position then. With the cover off I can see where the wires go, but not sure how that part works.

Someone said the 2G VS has a metering rod next to the actuator to get position feedback, so maybe something in that small round blue device needs to be replaced.

[Burgerman]

Permobils have twice as many wires as other chairs. So no idea what the blue thing is or what it connects to. But you may be right.

Take apart and see what it is/does. Might be obvious then.

[DSmidgit]

That blue thing is a potentiometer. It is used to measure the length of the actuator. If that isn't working correctly it could be giving errors. I have not seen one of these that where faulty but I don't have a permobil.

[Burgerman]

I am not sure that it is.
The wires are in the wrong place, should be radially positioned on a pot. And its too deep. And the size of those wires is the same as the current carrying ones to the motor. And a pot normally has say 10k or 500k written on it too. That soldering is abysmal. Well not the fact that its soldered badly but it should have heat shrink.

Its obviously doing something. Maybe a type of microswitch, or something. Take it apart! Only way to know.

[Burgerman]

You may be right! I found this after a lot of searching!

$3

https://www.walmart.com/ip/10K-Ohm-Rota ... /771634533

Measure its resistance after desoldering it and order a new one.
There will be lots of values. Measure whats there. Order and replace. Or get one from permobil $500.99.

Measure yours between terminal 1 and 3 -- the two closest to the actuator. It will be close to 1, 5 10k or something. You dont HAVE to use the same blue one, as long as it physically fits any similar value pot should work.
Remove wires or at least unplug from the permobil seating box first.

[shirley_hkg]

Probably bad contact only.
Open it, or drill a tiny hole, and spray contact cleaner.

[jefferso]

Probably bad contact only.
Open it, or drill a tiny hole, and spray contact cleaner.

I ordered a replacement on ebay but didn't get around to doing anything for a while. I re-checked and found the old one is a 1K and the one I ordered was a 10K.
I wasn't sure how to open or where to drill so took the 10k one apart.
Seemed to snap back on fine so tried it on the one still on the chair.

Was able to open it, but it didn't snap back on like the other one so put some gaffer tape across it for now.
Sprayed contact cleaner on it twice, let it dry, then tried plugging everything in again. Chair still doesn't move with everything plugged in. But it will go into standing mode and move while standing. When it comes back down (most of the way, but the seat is still elevated) it doesn't move. Unplugged, it moves again.

Text was hard to read in old photo.
MEXICO
BOURNS
3590S-A49-102L
RES 1KOHM +/- 5%
LIN +/- 0.25%
1017018
1020M

Took end cap off (think some plastic tab might have broken)
sprayed contact cleaner inside
taped end cap back on

Text on wrong replacement
MEXICO
BOURNS
3590S-2-103L
RES 10KOHM +/- 5%
LIN +/- 0.25%
1907M

[Burgerman]

You will need one thats a 1k pot. Reorder... If thats the problem, and it probably is since these pots die fast as the carbon surface is the resistor and it wears then a straight swap will likely do the trick.

[jefferso]

I ordered a 3590S-2-102L which is 1K

The Permobil one is 3590S-A49-102L

Any idea what the A49 part means?

3590S-1-102L also exists and something said the "1" indicates Plastic Bushing instead of "2" for metal bushing but not sure if that's right.

[Burgerman]

No. But just order a 1k pot. Numbers dont matter! As long as it fits.

[slomobile]

Sometimes the letters matter. For example an audio pot, often marked with a B, is not a linear resistance scale. That isn't an issue here however.

[jefferso]

I ordered a 1k

MEXICO
BOURNS
3590S-2-102L
RES 1KOHM+/-5%
LIN+0.25%
1907M

I found out some of the differences between 3590S-2-102L and 3590S-A49-102L
The metal turning post is longer on the one I got. Also, the post is slightly narrower so the black plastic gearwheel which fits on the 3590S-A49-102L with friction just slides onto the post with no friction so it wouldn't turn the pot when the gear turned. We ended up cutting the post down with a hacksaw, since the slot at the end is not used, so it will fit into the actuator. Then gave it one wrap with thin tape to it was hard to push the gear wheel over the metal post and now it turns with the gear wheel.

Comparing original (left with tape) to new.

We tried to set the turns to the same place (almost all the way open when in standing position). Put everything back together again, soldered the blue white and red wires back on and nothing has changed. Still has the same symptoms. If the standing actuator is unplugged the chair will move. If it's plugged in, it will stand, and it will move while standing, but about 25% down from standing, the first light on the ICS buttons turns red and it will no longer move. And the joystick only goes between M1 and recline.

Inside the actuator. Photo missing the creme coloured gear wheel which sits next to the black gear wheel.

I was able to use the Permobil "Take me down" mode (press and hold buttons 2 and 6 while off, turn on and hold for 30 seconds until all lights red) to get the chair to lower from the partly elevated mode which is at the end of the lower of the standing mode.
Take me down mode works to elevate or lower (very slowly) when the standing actuator is unplugged, so the chair can currently be used as a backup if someone is around to plug or unplug if I need to stand.
Who knows when the whole thing might stop working though…
I'm going to have to do more troubleshooting and/or decide if it's worth investing any more to keep this 2010 C500 working as a backup.

I saw a really good condition F5 (2019?) on ebay a while ago and am now wondering if I should have tried to get it.

[Burgerman]

Why permobil? They are very problematic.

[jefferso]

Why permobil? They are very problematic.

It's what I'm used to. The standing feature is pretty important to me. It's the flying car of wheelchairs but being able to stand, even when I'm not at home, is worth it.

I could have a backup chair without the standing feature, but I'd certainly miss it.

[Burgerman]

Fairynuff.

[shirley_hkg]

I tried to set the turns to the same place (almost all the way open when in standing position). .

It memories a special Ω value to denote the right position. May carry out several tries to find it, or run a self calibration.