Weird stains on Agilent DSOX 3000 display - Page 1
Forum section: electronics / testgear

author: papo
author_rank: Regular Contributor
timestamp: October 01, 2016, 10:31:11 am
content: HelloSomething happened to the display of my 3 year old DSOX3000. I was quite shocked when I discovered this yesterday morning. It's as if it was cleaned with some weird chemical but I only ever touched this with a moist cloth, the scope has been sitting on this very spot for 3 years and I always cover it with the towel on top to protect it from direct sunlight when it's not being used.I have calmed down a little because it's not as bad as it looks in the picture. When I uncovered the instrument yesterday morning the sun apparently was shining at it at a very particular angle where it's particularly visible.In any case I'm wondering what has happened there. Of course there's no way to prove it but I don't abuse any of my instruments and that also holds for the expensive ones. I purchased this towards the end of my studies and was happy to spend a little more to get something durable. Am a little disappointed.Lastly, the main reason for my post is to ask if anybody knows if there is a protective plastic window on top of the display or whether I'm looking straight at the display itself. Somehow those smears look like they are on a deeper level than the dust particles ons the surface. Maybe I'm looking at something trapped between the display and such a cover? One can always hope for the best. Unfortunately I cannot figure out whether such a cover exists from Dave's teardown videos, nor from the Agilent Service Guide. But maybe somebody knows.Regards and thanksMatt

author: _Wim_
author_rank: Super Contributor
timestamp: October 01, 2016, 11:28:12 am
content: I does indeed look like some moisture between 2 layers. I think the suggestion of blueskull to put it in a dry warm place is a good one, but I personally would not go as far as an oven. You could stored it in a box with some silica gel to get really low humidity inside so mthe trapped moisture can evaporate. Put the box in a good warm place.

author: andy2000
author_rank: Frequent Contributor
timestamp: October 01, 2016, 03:01:00 pm
content: If there is an air gap between layers, it could be from out gassing of the various plastics inside the case (similar to the way the windows on a new car get foggy on the inside). It could also be damage to the anti glare coating (if it has one). The iridescent lens style coatings don't take much abuse before they start to wear away in areas.

author: Augustus
author_rank: Regular Contributor
timestamp: October 01, 2016, 03:13:33 pm
content: It's hard to tell from the image. It could be damage to the anti-reflective coating or it could be trapped humidity (it's autumn and temps dropped significantly, the towel may have obstructed airflow and the trapped air in the scope may have reached dew-point). Quick check: Press (gently) with your fingers on the screen (several points). If the "stains" stay the same, position, form and size, it is likely damage to the anti-reflectice coating. If they change it's likely trapped humidity or delamination of the display stack.

author: nanofrog
author_rank: Super Contributor
timestamp: October 01, 2016, 04:41:13 pm
content: FWIW, I'd try putting it in a box with an incandescent light bulb as a heat source to remove any moisture between the layers, assuming the cause is trapped humidity between the display layers. Disassembling the screen configuration prior to trying this will really help if moisture is genuinely the culprit.

author: kilobyte
author_rank: Regular Contributor
timestamp: October 02, 2016, 12:40:38 pm
content: I also noticed this strange stains between the protective glass and the display.Good that it's not directly visible if it's running.

author: papo
author_rank: Regular Contributor
timestamp: October 02, 2016, 01:08:44 pm
content: Quote from: kilobyte on October 02, 2016, 12:40:38 pmOh wow those look exactly like mine. Are you sure there is a protective glass there? If yes, I will take it apart and wipe it off. I've been a bit reluctant to do so because of strategic warranty reasons but then again warranty has expired already so it would be up to them anyway. Also I was a bit scared of the various strategies outlined above involving ovens and filament bulbs (thanks for the suggestions guys!) but wiping it off the protective cover seems easy enough.Regards and thanks! Matt

author: jjoonathan
author_rank: Frequent Contributor
timestamp: October 02, 2016, 01:17:49 pm
content: If you've got access to a big enough vacuum chamber, low P is typically a gentler way to drive off water than high T.

author: kilobyte
author_rank: Regular Contributor
timestamp: October 02, 2016, 01:29:52 pm
content: My scope is now 4 years old.The protective glass is glued, with some double sided tape, to the display.This can be seen in one of Dave's pictures.https://www.flickr.com/photos/eevblog/5736045127/sizes/o/So i think it is not that simple to clean it because the stains are behind the front glass and the display.

author: Augustus
author_rank: Regular Contributor
timestamp: October 02, 2016, 01:32:19 pm
content: I don't know... After noticing kilobyte suffering the same problem I think it's not caused by trapped humidity. I suspect partial separation of the display layer stack

author: salvagedcircuitry
author_rank: Regular Contributor
timestamp: February 28, 2019, 05:58:21 am
content: Has anyone found a way to repair or reduce this delamination issue? Just got a dsox 3000 series oscilloscope with this issue and debating on living with it or trying to mitigate it.The part number for the DSOX 2000 / 3000a LCD is: 75019-68707Link:https://www.keysight.com/my/faces/partDetail.jspx?partNumber=75019-68707

author: TheSteve
author_rank: Unknown
timestamp: February 28, 2019, 06:03:31 am
content: The LCD panel is fine, it is the anti glare glass panel in front of it. It is held on with double sided tape. You can gently warm it up and then use dental floss or fishing line like a saw to lift the glass panel. It will clean up just fine with some monitor cleaner and can then be reinstalled. It should look good as new when done.No idea what causes it.

author: salvagedcircuitry
author_rank: Regular Contributor
timestamp: February 28, 2019, 06:09:06 am
content: Quote from: TheSteve on February 28, 2019, 06:03:31 amHuh. It sounds like you've done this beforeCool.I was thinking of heating up the outer layer (as shown in the above flickr photo from dave) and experimenting, but I didn't want to risk a $600 lcd. Crazy.Do you know if it is just the anti glare layer peeling off the outer glass? Do you think I would be able to reuse the original anti-glare filter after removal and cleaning, or would I have to source a new anti glare layer elsewhere and apply it to the glass? I could probably pull off an anti-glare layer from a computer monitor and cut it to size for reuse. Hmm.Thanks!

author: TheSteve
author_rank: Unknown
timestamp: February 28, 2019, 06:32:16 am
content: You can put the original glass right back on, it just needs cleaning.Yes, I have done it before.

author: quintin
author_rank: Newbie
timestamp: October 03, 2025, 01:13:09 pm
content: Hi,out of curiosity, how did you solve this? I ran into the same thing.Looking forward to your reply.

author: papo
author_rank: Regular Contributor
timestamp: October 07, 2025, 07:53:23 pm
content: Quote from: quintin on October 03, 2025, 01:13:09 pmHello. Assuming you are asking me: I never cleaned them. The stains were quite ugly when the scope was off, but didn't really affect readability too much when it was running. At some point, I had the unit serviced and calibrated by Keysight and I was disappointed that they couldn't be bothered to clean it. I later ran into the usual power supply problems with the unit (well documented in this forum), which further raised my disappointment with Keysight. I remember that I purchased this scope as a student, spending the extra money hoping to have an instrument that would be a companion for the better part of my professional career and I feel a bit let down on that...I hope this answers your question. All the best!Matt