Solve the Mystery! Help Me Removing Back Cover Rigol DS4024 Scope

• Solve the Mystery! Help Me Removing Back Cover Rigol DS4024 Scope
  Posted by Paul Price on 16 Jul, 2017 17:08
• I removed the four T10 screws from the back handle and bottom, but I cannot get the back cover to come off.  It seems to be binding somewhere in the middle of the back panel. I can insert flat-bladed screwdrivers and separate the cover a 1/4-inch or so on all sides, but that is as far as I can go to get the back cover to come off.
  
  What am I missing?
• #1 Reply
  Posted by jjoonathan on 16 Jul, 2017 17:14
• It's under the label with the serial number, IIRC. There are more like it on the front panel
  
  EDIT: NOPE, my bad, it's the label *above* the serial number, the one with CE, LXI, etc. Apologies! https://youtu.be/_J1pVlqMIHM?t=332
• #2 Reply
  Posted by Paul Price on 16 Jul, 2017 17:19
• I removed the serial number label, but there is no fastener to be seen there!
  
• #3 Reply
  Posted by jjoonathan on 16 Jul, 2017 17:19
• Oh no, I didn't get my edit there in time! Sorry, man!
• #4 Reply
  Posted by Paul Price on 16 Jul, 2017 17:24
• The area of above the serial number showing the safety compliances appears to be outlined by a very slim margin line, but it doesn't seem to be anything removable, it seems to be part of the cover.
  
   If it is removable, how do I remove this piece of  plastic without damaging it. It is plastic, not a label and seems to be part of the back case.
  
• #5 Reply
  Posted by jjoonathan on 16 Jul, 2017 17:28
• It's a thick foil label, like the front panel sticker, unless they've changed the design. That's why Connor Wolf used a razor to get under there in the video I linked.
• #6 Reply
  Posted by Paul Price on 16 Jul, 2017 17:34
• It is not a foil label at all. It is made of the same type of plastic as the rest of the back cover.
  
  I haven't tried to dig into the margin yet with a utility knife or razor to somehow cut this piece of plastic loose from the back case.
  
  But you  must be right, there is no other place a hidden screw on the back of the case can be hidden. Tell me I must operate!
  
  
  
• #7 Reply
  Posted by jjoonathan on 16 Jul, 2017 17:45
• I remember having the same fear. It was much thicker than I expected, but in the end I was able to use a razor to peel up a corner just like Connor Wolf did. Maybe you could try a plastic razor or spudgers first?
  
  It's possible that they've changed the design, but I doubt it. Why bother? It's a label on a 5 year old scope line. They've got better things to be doing launching the Phoenix scopes.
• #8 Reply
  Posted by Paul Price on 16 Jul, 2017 17:46
• Thanks jjoonathan, you got it right on the second try!
  
  Ahah! I didn't see the attached link to the video on how to do this. I was able to pry the label up a bit to expose the hidden T10 and bingo, the cover comes off, but at the expense of ruining the appearance of this label, now forever creased and maybe only super-glue will get it to remain flat again!
  
  Thanks Rigol! for making it so easy to service my scope and publishing a service manual that says only four T10 screws need to be removed.!
• #9 Reply
  Posted by Paul Price on 16 Jul, 2017 17:58
• The Horiz. Scale rotary encoder has gone bad, even if this scope is only a few years old.  I need to find a replacement or attempt to remove and disassemble the old one to try to make a repair.
  
  Would anyone else point out any other gotchas that I need to know about to get to the rotary encoder and repair it?
• #10 Reply
  Posted by jjoonathan on 16 Jul, 2017 18:06
• Darn, you're going to have to remove the front sticker then. There are three screws under it. There's a diagram lurking somewhere on the eevblog forums that shows the locations but I can't find it. If I were you, I'd invest some time in hunting it down.
  
  This is going to involve pulling up maybe 1/3 of the whole sticker, starting at the left. With a heat gun and patience you can do a clean job of it.
• #11 Reply
  Posted by TurboTom on 16 Jul, 2017 18:18
• That's correct. I replaced both the menu and digital functions encoders on my MSO40x4 with detented ones. Having to remove the two (or were there three?) hidden screws under the front panel sticker is a real PITA... But careful application of some heat eases things up a lot. What's iportant is to pull off the sticker at a rather shallow angle or it will catch at the encoder shafts. Sometimes this cannot be completely avoided but the knobs cover the distorted areas of the sticker well enough to hide it. I wonder why Rigol didn't go for some more screw holes in the PCB(s) and assemble everything from the rear... Then again, the DS4000 series is rather old meanwhile.
  
  Good luck,
  Tom
• #12 Reply
  Posted by Paul Price on 16 Jul, 2017 18:23
• Here's the how to from the Rigol DS4000 Service Manual(The same manual also fails to show/mention the hidden screw in the back.)
  
  Is this drawing correct? Notice that the manual doesn't mention the sticky business of removing the peel-off front panel!

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• #13 Reply
  Posted by jjoonathan on 16 Jul, 2017 18:31
• The two hidden screws shown in the diagram are in positions that I remember. I do not remember where the third screw was, if it was there at all. I do remember that the screw between the ch2 and ch3 position knobs was the last one (I started peeling from the left), so if you follow that same strategy you should be covered for both possibilities.
• #14 Reply
  Posted by Paul Price on 16 Jul, 2017 18:39
• Peeling open a wound and it never heals.
  
  What does anyone  think of carefully locating the screws to be removed and then carefully cutting a round access hole in the front sticker with an Xacto razor knife, later to be covered up with a tiny square or round piece of glued-on white plastic to act as a covering  band-aid/plaster.
  
  I dread the thought of ending up with a front panel that is creased or repeatedly tries to peel off. If another rotary encoder fails, then I will have to peel again. Please don't make me peel again!
• #15 Reply
  Posted by jjoonathan on 16 Jul, 2017 18:41
• I think that patches look worse than creases, but that's a matter of opinion.
  
  As for not peeling twice, just don't replace the hidden screws. There are plenty of non-hidden screws to maintain structural integrity.
• #16 Reply
  Posted by Paul Price on 16 Jul, 2017 18:44
• Thanks jjoonathan, sometimes having a screw or two loose is a real boost.
  
  The secret of not having to be screwing around with stickers maybe is in finding patches that matches.
  
  I recently repaired a tiny pothole upon a large dinner table that had a hard white  plastic veneer top with a dime-store fixit kit that melted colored hotwax that perfectly covered up the hole and color matched so well that  the repair disappeared from view. The wax patch became almost invisible and was easily leveled to match the overall flat surface with just a small finishing scrape with a flat razor.
  
  In the end, funk rules function and appearance becomes less important to me than having the ability to quickly repair this instrument and getting getting back to work.
  
  Several people have commented that this scope is old news, but what scope are they using that matches the price and capability of the scope I now have?
• #17 Reply
  Posted by jjoonathan on 16 Jul, 2017 19:51
• Old doesn't mean bad or bad value. In fact, I think the primary competitors of the DS4k would be much older (TDS3054 and such).
• #18 Reply
  Posted by Paul Price on 16 Jul, 2017 19:55
• There is a third screw hidden binding the front panel. By wiggling around I can tell it is located somewhere near the top of the Chan 1 vertical position control..but exactly where?
  
  
  Like any surgeon, I need to know where to make the final cut!
  
   I have managed to use an Xacto knife to cut out small squares of the front panel plastic label surrounding the other two screws and they can be easily pasted back in place to cover up the screw access hole.
• #19 Reply
  Posted by TurboTom on 16 Jul, 2017 22:36
• Check if the removed screws are ferromagnetic, and if so, use a small magnet to search for the position of the remaining screw.
  
  I mentioned that the DS4000 series is quite old -- I guess it dates from around 2011. Of course this doesn't imply that it's not a decent instrument with a lot of value for the money. I only meant to say that Rigol may have learned and omitted these stupid hidden screws in their later products, as it seems.
  
  Cheers,
  Tom
• #20 Reply
  Posted by Paul Price on 16 Jul, 2017 22:48
• Searching on the net, I found that there was a newer version of the DS4000 Series Service Manual Oct 2014 which shows the third screw!
  
  The size of the User Manual  file is ~1.5MB and so, unfortunately I cannot attach it to help others.

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• #21 Reply
  Posted by jjoonathan on 16 Jul, 2017 22:55
• Nice! Good luck with the encoder swap!
• #22 Reply
  Posted by Paul Price on 16 Jul, 2017 23:11
• Where to download the latest versions of manuals for DS4024 scope:
  
  http://www.produktinfo.conrad.com/index.php?type=&lang=&bl=EN&q=rigol+DS4024+oscilloscope
• #23 Reply
  Posted by martys on 22 Jul, 2017 11:52
• Helpful advice for others attempting to replace a bad rotary encoder in their Rigol DS4000 series:
  
  I also had trouble with rotary encoders on my Rigol DS4000 series scope and since it was out of warranty,  made my own repair.
  
  I had a rotary encoder w/push button that began to fail within six months before the end of my three-year warranty. I couldn't do without the scope on my workbench for a week or two, so I decided that when the control became really unusable, I would fix it myself. After all, I been designing circuits and building electronic devices for years and I know enough how to repair these things.
  
  Some time after my warranty expired I contacted Rigol Tech support about purchasing a replacement rotary encoder from them and they told me they are not in the business of selling parts and they said to get it repaired I must ship it to them and they quoted me a repair price of close to 50% of the original scope purchase price, not incl. the high cost of insurance and shipping, just to replace an approx. $4 USD  part.
  
  (1) Bourns makes an exact fit replacement part PEC11R-4215F-S0012   (12 detents/rev)
  This one has a push-button sw. and detents.  Available from Mouser, inexpensive and in stock. It is hard to find a 15-mm shaft length  like the original at other major part houses not stocking Bourns parts. Alps doesn't make one that fits.
  
  (2)There is a small satellite control board(Clear Auto Single Trace..etc) delicately attached to the top right corner of the control panel PCB. It is connected to the control panel with a very delicate and much too short plastic flex ulta-flat cable that is so easily damaged, as I have proven to myself. With just a few movements this cable end soldered on the satellite board sheared off like it was cut with a razor and I had to really search around eventually found a used and much wider flex flat cable to effect a repair. I had then to trim it with a scissors, slightly strip the cut end with emery cloth, then solder it in. Finally, a bit of hot glue applied on the flat cable near the soldering point was needed to ensure the cable was was fixed in place and could not move about to shear itself again.
  
  (3)Rigol has slopped on acrylic caulk-like hard white robot snot all over delicate ultra-low profile flat cable connector sockets and it is impossible to repair the scope without first disconnecting the flat cable interconnects to allow access to the underside of the control panel board to unsolder parts. It take some care and time-consuming scraping with a razor/flat screwdriver tip to remove this stubborn gook without damaging these delicate connectors. 
  
  (4)As already mentioned by Paul, Rigol has had the bad sense to fasten the front panel with three small screw hidden beneath the front panel decal and this means the decal must be very carefully unstuck from the front panel metal without creasing it or damaging it. IMHO three hidden screws are not really needed, but like the single hidden screw on the back cover under the Safety Conformance label. these screws might have been added just to discourage people from servicing their own equipment. Repeatedly removing this decal will eventually mean it will not re-stick and the scope then becomes techno-junk when looking at the cost of having Rigol replace the sticker front panel. The problem is, from what I've read about may people having trouble with their Rigol scope's rotary encoders, they seem to fail often and some time in the future I will have to replace another on my scope.
  
  Don't get me wrong. I still am quite satisfied with the quality and performance of this scope when I justly compare it to the much higher priced scopes from Agilent or Tek. I just wish it was more reliable and easier to repair. I have a Tek 475 scope that's old enough to have grandchildren and all it still works perfectly and was easy to repair when once it did go sour.
• #24 Reply
  Posted by rs20 on 22 Jul, 2017 11:53
• Quote from: martys on 22 Jul, 2017 11:52

  (1) Bourns makes an exact fit replacement part for a rot enc with push-button sw. and detents.  Available from Mouser, inexpensive and in stock. It is hard to find a 15-mm shaft length rot enc like the original at other major part houses not stocking Bourns parts. Alps doesn't make one.
  

  
  This advice would be 100x more helpful if you provided the part number.