G'day,
I've done a search but could only find this:
https://www.campbellsci.com/forum/messages.cfm?threadid=511890A1-A17E-6A84-A8DBA9CDED3BC1F9
I've got 80+ CR850s, for the last year or so we've had issues with the display screen being blank at site visits. We've been swapping loggers and sending the unserviceable items back for repair. Some of them have been repaired more than once. At one stage recently 13 loggers were in for repair, more than 15% of my stock, several have been sent back to the US for assessment. Some of the loggers returned for repair have been returned with no fault found, yet the screen was blank when removed from site. I've heard from hydrographers in other Australian States that have had similar issues. It would be interesting to know how widespread the issue is, and if anyone has discovered a cause or solution.
Cheers,
Mick.
Mick,
Thank you for your post. We have been working with Campbell Scientific Inc. in Logan Utah on this issue.
To address your question about how widespread this issue might be - to date, we have two customers (including yourself), both in Australia who have experienced this issue. At this stage, we continue to believe that it is a hardware fault in the display however we are working with the original supplier to find the root cause. We have already dispatched replacement CR850's to you (19/12/2012) to help boost your spare stocks while we continue to investigate the cause of this problem.
We will be in touch with you shortly to provide a more detailed update.
Regards,
Alex.
Alex Thomas
Operations Manager
Campbell Scientific Australia Pty. Ltd.
One thing that would be instructive to try would be to repeatedly press the right arrow key on a field unit that has a blank display.
The thinking here is that due to temperature the LCD is contrast limited. Pressing the right arrow on the display, while the CR800 is at the top most menu, increases the contrast on the display. This new setting is saved in non-volatile memory and used as the bias offset there after.
There is a temperature compensation algorithm in the firmware of the display, but some displays have a lower bias level than others, and also show different non-linear behaviors over temperature.
This simple test may save you from shipping units back to us.
Dave Madsen
Dave,
Thanks for the suggestion, however we have been in contact with Mick (outside the forum), have evaluated several of his CR850's exhibiting this problem and have already been able to rule out a problem with LCD bias in the display controller.
Sample units have been sent to CSI for further testing and the QA team have been involved. Their testing seems to indicate an issue with the graphic module. The original manufacturer of the display module is currently studying some samples to establish the cause.
Please feel free to contact me by email if you would like to discuss this issue in more detail.
Regards,
Alex.
Alex Thomas
Operations Manager
Campbell Scientific Australia Pty. Ltd.
Hi. it was I who that posted the original post that Mick refers to.
Can you give me some more info about this problem?
Is just Campbell Australia who is aware of this problem or is a more wider issue (i'm from Portugal, and I answer before Campbell UK!!)
Thanks
ZP
We, at CS UK have been monitoring this situation and have discussed the small number of display failures we have seen in Europe (<2% at the last count) with our colleagues in the US.
We are waiting to be told of the outcome of the analysis of failures by the manufacturer.
Ok
Thanks aps. I'll be waiting for good news about this problem.
Cheers
Good afternoon,
We have several problems CR850 screen that looks dark and others with white screen. Where we can get solution to this problem.
We have tried to solve this by moving the screen contrast, but there is no change.
The last I heard was there was an issue with the connection/interface between the screen and the rest of the logger hardware. As far as I'm aware, CS have been working on a resolution with the original manufacturer of the screens.
Sorry for the delayed update. We have been working on this for several months to determine the problem and provide the best solution.
The problem has been narrowed down to the application of the display IC to the LCD glass. If the proper heat and pressure are not used during the display production process the adhesive, which contains conductive partcials, will not engage the pads on the IC with the pads on the glass correctly. This can result in degradation of the adhesive. Two factors that are prevalent in this degradation are high temperature and high humidity.
The symptoms that will be noticed in the field are displays that blank out, go dim, have a low contrast voltage, or blank out after a short time voltage is applied. They appear to be displays that have been in the field a few years with exposure to high temperatures and humidity.
Inspite of months of work with the original manufacturer, we have failed to reach a satisfacory resolution to this display problem. We have thus identified a new display supplier. We are two weeks into a 2 month comparison test with displays from the new supplier and the old manufacutrer. We are exposing the displays to high humidity and high temperature. We have had 3 displays from our old supplier go dim. All of the new displays are still working great.
Thank you for your patience. We are getting close to a resolution.
Thanks for the update, much appreciated. Although some of our sites may see high temperatures, most do not, but a high number do see consistent high humidity. Then again, it depends on what you consider to be high temperatures. Few of our sites would see below -5degC or higher than 35degC.
Cheers,
Mick.
I've been purposefully vague with what is high temp and high humidity. For our accelerated testing, we are using 90%RH at +50°C. We’ll try to kill them so we know they won't die in your application. Humidity, especially condensing, is an electronics killer. A preventive maintenance plan that includes replacing enclosure desiccant is always recommended. Still, no excuse for the premature display failure.
We have taken into account the relative humidity and control with granular silica gel, which is replaced periodically.
In addition we created in the program of datalogger, an alert humidity with a variable type booleam, when a maximum moisture condition is met, it is sent and visualized on the RTMC.
The relative humidity measured with an sensor CS210 Enclosure Relative Humidity Sensor.
We hope we can help with anything to solve this problem, either by testing or some action to our attention.
Thanks for your attention!