Problem with rigol scope knob

[Simon]

I've been having a problem for a while now with my rigol DS1102E (was DS1052E), the horizontal scale knob is rather erratic, often one "click" jumps the scale by two scales or even it goes the wrong way, ie i want to increase the s/div but it reduces or vice versa.

Now as far as i know the know is physically ok, the roughest the unit has had is carrying it in a rucksack but really that should not case a problem to 1 knob that is less delicate surely than the thinner and taller ones.

has anyone else had this ?

is the firmware upgrade worth it ? maybe corrects this ? but the scope did not do it in the beginning and I think it's getting worse

[Kiriakos-GR]

Exchange it with a Burns ....   

[Simon]

burns ?

[Kiriakos-GR]

Bourns ... Mexico ..    http://www.bourns.com/ProductFamily.aspx?name=potentiometers
Can you take a picture of it ( rear side ) , or write the specs of it ..

[JohnS_AZ]

The thing is probably a shaft encoder, not a pot.

[safarir]

Exchange it with a Burns ....    

The horizontal knob is already a bourns, model PEC11-4115F-S0012

As you probably knob, when I receive my scope, my knob was broken. I replace it with a PEC11-4115F-S0018 since I could not find the PEC11-4115F-S0012. My have 18 step my turn compare to 12 step by turn but it works just find. It easy to skip a step but if you realy want to increment just by one, it not a problem

[Simon]

well it's starting to be a pain in the ass and I'm no longer impressed ! jeez at this rate I'll be learning how to use ASCII on a pic and I'll just go rebuild the damn front panel. How easy is it to change the knob, are they really that fragile ?

[TopherTheME]

One of the Teks in my lab at uni does this. It doesn't use a pot but a rotary encoder like mentioned above. I just push it to one side while I turn the knob and it seems to solve the problem. Other than just replacing the encoder I don't know how you could fix it. If its not sealed you could try spraying the encoder with a wax or teflon based lubricant.

[Simon]

One of the Teks in my lab at uni does this. It doesn't use a pot but a rotary encoder like mentioned above. I just push it to one side while I turn the knob and it seems to solve the problem. Other than just replacing the encoder I don't know how you could fix it. If its not sealed you could try spraying the encoder with a wax or teflon based lubricant.

hey that works, thanks

[Mechatrommer]

i have the same problem, but not erratic, its just the changing is very slow unless i put extra push to the knob while turning to get normal interval changing. cant remember which knob.
edited: it only affect one direction, the other direction is still ok.

[Simon]

oh mine just goes haywire, back instead of forward or jumps steps - very annoying: thumbs down Rigol

[rossmoffett]

oh mine just goes haywire, back instead of forward or jumps steps - very annoying: thumbs down Rigol

This happens with pots from time to time.. dirty or worn contacts, possibly even bent.  My car radio does the same thing with its "seek" knob.  Gotta remember they didn't manufacture everything, they chose normally reliable parts and you got one of the lemons.  Send it in for warranty repair or if you  bought from China like I did those are the breaks, just replace it. 

[Simon]

I can't send it in for warrantry as I've opened it, hacked it and smashed the power switch. It looks like pulling it to one side works fine and well maybe an ascii pic driven control panel would be a cool project one day

[wd5gnr]

Same problem here with the trigger level setting :-( I know the Kenwood encoders sometimes respond to having a motor attached to the shaft and just having the hell turned out of it. Are the encoders sealed? Of all the knobs this is one of the better ones since you can go to 0 or 50% without using it and that's usually adequate. But still

Might look into warranty but I guess I'd have to put my original S/N back in.

[Simon]

well for warranty mines trashed, broken power switch and plenty of marks to show that I opened it up needless to say warranty label cut.

Anyone planning for a custom control panel to control the scope via RS232 ? a cool twist could be having custom setups that can be recalled and other cool controls. I've never done RS232 before though but it's something on the list now of todo's

[Mechatrommer]

well for warranty mines trashed, broken power switch and plenty of marks to show that I opened it up needless to say warranty label cut.

reopen it and clean the knob encoder yourself .

[wd5gnr]

Well that's why I asked if they are sealed or not. If they are sealed its a lot of work to remove the case and probably no benefit. If they aren't sealed then a little spray cleaner would take care of it.

[Mechatrommer]

Well that's why I asked if they are sealed or not. If they are sealed its a lot of work to remove the case and probably no benefit. If they aren't sealed then a little spray cleaner would take care of it.

no they are not. i've disassembled and expose the panel board (encoders) quite easily. i think just a desoldering the encoder and proper cleaning method should be able to get it back to life. but i'm not sure if the encoder is using a new "mechanical" way as opposed to what i already used to see.

[kderh]

I have the very same problem with my 1052, the horizontal scale encoder is unreliable. When i turn it to zoom out it sometimes jumps or goes back (especially if I turn it quickly), but it works perfectly when i try to zoom in.
I found out gently pulling the knob while turning slowly helps, then it registers properly.
Considering I always treated the unit well, thats kinda disappointing. Or is it a software problem? Began noticing it some time after upgrading to the latest firmware...

[Mechatrommer]

annoyingly. when i press multifunction knob to reset something, it will pop the help menu out, sux! its ok if the menu is popup and cancelled quickly, but! we have to wait the progressbar to complete loading for several seconds before the help menu popup, sux! and the rotation sensitivity is sux too! i think thats the cheapy encoder they are using.

[M.Hassem]

If you can find a good replacement, from a mechanical point of view (it fits the original place), you might try using an optical encoder with the same output as the mechanical one these things have.

Optical encoders last more and are more reliable. But they're a hell of a lot more expensive!

[sonicj]

i wonder if someone forgot to debounce that encoder?
-sj

[Simon]

a possibility except that these faults seem to occur after some time, if there was a lack of debouncing then it would happen since day one ?

[sonicj]

might be that a factory fresh encoder doesn't reveal the debounce oversight, but as the encoder breaks in, loosens up, grease gets pushed aside, etc. a contact bounce can occur.
-sj

[Simon]

right so the bouncing issue is down to failure of the mechanics of the switch/knob