EEVblog Electronics Community Forum
General => General Technical Chat => Topic started by: Simon on September 11, 2010, 08:52:33 pm
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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
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Exchange it with a Burns ....
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burns ?
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Bourns ... Mexico .. http://www.bourns.com/ProductFamily.aspx?name=potentiometers (http://www.bourns.com/ProductFamily.aspx?name=potentiometers)
Can you take a picture of it ( rear side ) , or write the specs of it ..
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The thing is probably a shaft encoder, not a pot.
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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
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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 ?
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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.
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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
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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.
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oh mine just goes haywire, back instead of forward or jumps steps - very annoying: thumbs down Rigol
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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.
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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
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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.
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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
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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 :P.
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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.
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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.
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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...
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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.
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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!
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i wonder if someone forgot to debounce that encoder?
-sj
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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 ?
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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
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right so the bouncing issue is down to failure of the mechanics of the switch/knob
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right so the bouncing issue is down to failure of the mechanics of the switch/knob
No, all mechanical switches bounce. And bouncing behavior can change over time, which is not a failure per-se. If there is no proper debouncing it is a design failure - typical mechanical switch behavior hasn't been taken into account.
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I've seen this too, brand new switches and knobs are great you could clock your PC off the nice clean edges that they produce, a few months later and the wave form they produce looks like a lunar landscape.
You could probably check this with your oscilloscope! I am laughing just picturing the scene now. Debugging a faulty scope with said faulty scope.
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OK after my horizontal scale knob became totally random I decided to open the scope and clean the encoder, and now it works much better than before as it skips very rarely now.
If someone wants to try this here are some tips:
-Heat up the warranty seal with a regular hair blower, then you can peel it off without damaging it
-There are 2 screws under the carrying handle
-Do not touch the 2 screws next to the power socket for now, remove them later.
-To get the power switch out of the way, simply pull it out with pliers.
-Wiggle the back case around until it comes off
-Remove the other shielding elements (back, top)
-Remove all the front knob caps ( just pull them off)
-Remove the power supply as there is an additional screw behind it that holds the front panel
-Disconnect the input board by lifting the white flex cable off the main board
-Remove the other screws holding the front panel, then you can take it off
-Remove the input board (careful with the flex cable)
-Desolder the bad encoder and lift the 4 hinges on all sides to open it (or just replace it with a new one)
-Clean all contacts inside (I used a Q-tip)
-Reassemble the encoder, solder it in and reassemble the whole unit
This worked for me, hope it stays this way for some time... Mechanical encoders suck...
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Great job, kderh, all you need are pictures and this is a perfect hack/fix.
OK after my horizontal scale knob became totally random I decided to open the scope and clean the encoder, and now it works much better than before as it skips very rarely now.
If someone wants to try this here are some tips:
-Heat up the warranty seal with a regular hair blower, then you can peel it off without damaging it
-There are 2 screws under the carrying handle
-Do not touch the 2 screws next to the power socket for now, remove them later.
-To get the power switch out of the way, simply pull it out with pliers.
-Wiggle the back case around until it comes off
-Remove the other shielding elements (back, top)
-Remove all the front knob caps ( just pull them off)
-Remove the power supply as there is an additional screw behind it that holds the front panel
-Disconnect the input board by lifting the white flex cable off the main board
-Remove the other screws holding the front panel, then you can take it off
-Remove the input board (careful with the flex cable)
-Desolder the bad encoder and lift the 4 hinges on all sides to open it (or just replace it with a new one)
-Clean all contacts inside (I used a Q-tip)
-Reassemble the encoder, solder it in and reassemble the whole unit
This worked for me, hope it stays this way for some time... Mechanical encoders suck...
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Well I got mine apart... encoder removed (vacuum really helps), cleaned, and resoldered. Now I'm about to put it back together. Wish me luck. Thanks for the steps ;-)
Bah! I got it back together enough to try it and it is no better (then again no worse). When I took the encoder apart, there was a membrane type switch in a green plastic frame and a white plastic ring on top with some position pins. The black part had a spinning disk of sorts. I used contact cleaner on both parts and scrubbed with a Q-tip. It didn't look like that I expected, but what do I know.
I'm debating if I want to take it apart again -- its a pain -- and try again. It appears to be an ALPS encoder -- does anyone have a source? I'm guessing its from this series: http://www.alps.com/WebObjects/catalog.woa/E/PDF/Switch/Encoder/EC11/EC11.PDF (http://www.alps.com/WebObjects/catalog.woa/E/PDF/Switch/Encoder/EC11/EC11.PDF) but would need a place that sells reasonable quantities.
Measurement wise the body is 12.5mm wide and 14mm tall. Shaft is 6mm in diameter. 14.4mm from the tip to the bottom of the body and 5mm shaft length.
Digikey has:
http://www.bitechnologies.com/pdfs/en12.pdf (http://www.bitechnologies.com/pdfs/en12.pdf) - 17.5mm reach bit 5,, shaft length. Maybe trim the shaft a bit. There were 3 "12mm" encoders with switches so I think I'll order all 3 and see how they might fit. The are only a couple of bucks each.
P12336-ND
987-1194-ND
987-1195-ND
1 of each is less than $5 total.
Sigh....
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Well it turns out I didn't have it completely apart last night which is why it looked like something was missing. Unfortunately, it still didn't clean so I'm going to try ONE MORE TIME.
The attached picture is the encoder apart (enhanced to show detail so a little grainy). The green part is the switch. What I had last night was that off but the black body of the encoder remained attached! Duh. You have to get the board lock legs spread apart to get the black part off.
I Q-tipped the encoder wheel (16 pads so I guess its 32 pulses per revolution?) an sprung the contacts a little with a screwdriver.
A few notes about taking the whole thing apart:
1) The white cable is in a ZIF socket. You have to release the two black tabs at either side of it and then it just comes out with no force. If you are pulling the cable you don't have it unlocked. It should just "float" out with no force.
2) The reason I mention this is that getting it back in is HARD. It is very hard for me at least to keep the ZIF lock open on both sides. The best method is to flip the scope upside down or at least tilting down in the right way so that the lock wants to fall down. Then once you get the cable in (should be none of the exposed metal showing) you can flip it back and push the locks down with a small screwdriver.
3) As far as I can tell the power supply bundle of wires has to come off the main board. I don't think the connector on the power supply comes off.
4) If you see an LED "broken" on the front panel board don't panic. Its for the logic analyzer and you don't have it (well, if you do, then panic). Looks like they make all the boards and just pop the unwanted LED off with a pair of dykes or something.
I'm going to try again. I'm getting pretty good at putting it back together.
Correction. I think it must be 24 pulses per rev. There are 3 contacts. So for 1/3 of the rotation any given contact is the common contact, the A contact, and the B contact. So per rev terminal A has 3 contacts brushing 8 pads for 24 pulses per rev. The good thing about this is I have figured out all the stuff I never knew about mechanical encoders.
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be carefull not to damage the parts, as the problem might lies outside it, not in the encoder. the device seems easy to clean/repair.. clean the contact pad and push the 3 contacts lever a bit outward, but not too much to avoid misalignment. you must have a way to verify that the signal is something like the pic below (from your EC11.pdf) (ie 3 phase signal). if you have verified the signal is ok, then i think the problem is not the encoder, it must be something else. Happy hacking ;)
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Yeah I thought the same thing. But I still think it is the encoder based on occam's razor and the fact that it got worse over time until now it is unusable. The last encoder I mentioned from Digikey looks like it should fit ok and the only real difference is it has detents. If it doesn't work than I will have to look at what's reading it. I did think of swapping two of the encoders but decided it wasn't worth the trouble since I have a new on en route. But if the swap caused the problem to stay it would have to be the circuit not the encoder.
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if you cannot verify the 3 phase signal, then easier for connectivity test for each pin while rotating the knob.
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Well it turns out it was both.
When I started out the encoder was "flaky" but you could coax it. Then eventually it got to where it would just "jitter" and just flop around the current position when you turned the knob.
I replace the encoder with Digikey 987-1195-ND. The fit was exact and since I'd had the other one open I knew it had the right number of pulses per rev. However, it has detents so you get a little click as you turn it. Otherwise perfect.
Replacing the encoder made it "flaky" again. You could get it to move but mostly only in one direction and sometimes randomly the other way. I opened it back up and there are two diodes behind each encoder. One of them read open both ways. I don't keep SMD diodes around (I have started keeping a bunch of SMD resistors around) but I managed to remove one off something I am not using. It was a Schottky diode (the one in there was something like a 1N914 I'd guess from measurements of the other ones) but judging what the circuit was doing I didn't think the forward drop was going to matter. Now it works like brand new!
Rigol has offered to send me a new UI board under warranty which is SUPER of them. Haven't got it yet though. I did buy from a US distributor, by the way.
I posted pictures of the tear down.
https://www.eevblog.com/forum/index.php?topic=2092.0 (https://www.eevblog.com/forum/index.php?topic=2092.0)
I don't remember if I mentioned in the notes but the only thing holding the back shield on is the jack nuts for the DB9. Be very careful as the metal work is not so good. I have a top shield screw that will no longer tighten, and one of the bottom case screws chewed some plastic and won't go in well either. But the case is a tight fit so you really can't tell. In fact, I've been leaving out the screws under the handles and can't tell the difference. I suppose if you had it bouncing in the back of a truck, maybe. But mine sits quietly on a bench.
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Rigol has offered to send me a new UI board under warranty which is SUPER of them. Haven't got it yet though. I did buy from a US distributor, by the way.
You are quite the master, going beyond breaking the warranty seal, and still getting warranty service! Awesome, plus kudos to Rigol for the service as well!
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Well it turns out it was both.
both what?
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Both the encoder and something on the board. Originally the motion was jerky in one direction and then it became almost nonexistent. Replacing the encoder got me back to jerky and replacing the diode made it work 100%. My guess is the diode was bad from the start. Then the constant pulling and twisting on the encoder to try to get it to unstick took the encoder out.
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so i guess it was the diode only, not the encoder. from what i understand of your post #35.
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No, I think it was both. Let me put it in time order.
1) New scope. I noticed that sometimes the trigger level was "flaky"
2) Soon I can only adjust the level up noisily. So you can reset to the baseline (push the button) and move up, so it was usable. At this point, I think the diode had completely failed.
3) Assuming it was the encoder I am twisting the encoder, trying to pull it out while turning, push it in, etc. Contact cleaner, compressed air, etc. Nothing helps.
4) Over a few months the problem becomes worse. Now twisting the encoder knob just causes the trigger level line to jump up and down maybe one step in either direction. The only way to get useful position is to use the 50% key. At this point, I think the encoder has failed.
5) I take the thing apart and clean and respring the encoder several times. No change.
6) I replace the encoder. Now I am back to the behavior in #2, so the new encoder did change the behavior. It just still didn't work.
7) Replacing the diode under the encoder restores normal function.
So I think the encoder was OK to start with, but eventually failed prior to me opening the thing up.
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ok, thanx for the report. will be helpful if some of us got this problem.
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Searched google about this and got this forum!
I have a month old DS1052E and have noticed its horizontal scale knob is jittery when trying to zoom in or out fairly quick. All the rest are fine. Still under warranty so pretty reluctant to open it.
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Ehh, apologies for ressurrecting a dinosaur (maybe it can be changed to a new topic IF necessary but I would keep it here under one place / same issue). :-[
I've found an unit that wasn't in use due to those flacky encoders.
Very well, followed the instructions and I have now used these encoders:
858-EN11-HSM1AF15 (https://www.mouser.ee/ProductDetail/TT-Electronics/EN11-HSM1AF15/?qs=%2fha2pyFaduhOYd5PyjIqpQ6YWbg4Lq7xVpCc4jAc%2f4vVut5QRFXGEw%3d%3d) - for channel timebase - works flawlessly.
For the other 4 encoders there's been suggested:
858-EN12-HS22AF20 (https://www.mouser.ee/ProductDetail/TT-Electronics/EN12-HS22AF20/?qs=%2fha2pyFaduh%2fIrEc67npXDGOoj1Dbna9z7Ixf2bYmqc1%2fUJobW6JBQ%3d%3d)
652-PEC11R4315FS0012 (https://www.mouser.ee/ProductDetail/Bourns/PEC11R-4315F-S0012/?qs=%2fha2pyFaduidMAYXvh4P%252bH09l1jEvlwNo0x3z8ZgWTL7PU3iF3yWY1vycsK0lPyt)
Some claim that these "work" but for both of them I see them skip many values. For the 'menu' encoder they skips about 3 values. For instance intensity increases/decreases in increments of 3.
Don't remember this happening on the original encoders.
Position is also incerementing in bigger steps. When I ever so slightly move the encoder I could get smaller increments but with dentents the steps seem quite uneven - not good.
So I've spent quite some bucks(euros :P) on testing different encoders for the menu and hor., ver. positions (ch and trig) but these 4 havent worked as expected. |O
Curiously enough I haven't seen any reference to what encoder one should use for that to work on Rigol DS1052E. Maybe someone can point me (and for future reference) to the 'correct' ones ?
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Have anybody successfully replaced the Horizontal position knob (or any of the 4 that look the same) on DS1052E ?
I saw several discussions about the encoders used, but I still miss clear answer what type is 100% perfect, either original type or a one that works exactly as original.
Some types mentioned became obsolete, some unable to find..
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I was able to solve the problem with additional capacitors on my OWON SDS7102. Should also help here, as the technology in the Rigol is often the same.
You can find the solution to the problem here:
https://www.eevblog.com/forum/testgear/owon-sds7102v-problem-with-encoders/msg3479200/#msg3479200 (https://www.eevblog.com/forum/testgear/owon-sds7102v-problem-with-encoders/msg3479200/#msg3479200)