Potential corrosion on external ports and pins

17 Jan 2024

Note: This information is provided as a reference and does not imply that Juniper Systems will provide full support for the use of any specific third-party protective coating, cleaner, or other substance with or modification to a Juniper Systems product.

The Juniper Systems rugged handheld computer products are designed to be as rugged and water-tight as is commercially viable. Even though our handhelds have successfully been used in the most extreme terrestrial environments, there are some environments which can still present a high potential for corrosion over time on externally exposed metal components (such as ports and docking pins). Long term exposure to salt fog and spray (operating around brine (sea water)) is one example of such an environment.

It is best to limit the amount and duration of such exposure, including quickly washing and drying off/out external ports and pins after such exposure. We have provided port covers (connector protectors), powder-coating (paint), internally conformal-coated field replaceable connector / port (I/O) modules, and historically stainless steel parts (see bottom of this article) as features of our handheld products which help or have helped to reduce such potential corrosion. Even a limited quantity of prototype docking pin covers are available for 7-inch Mesa models for use in extreme cases. In any case, when operating in such environments, you should expect some annual or bi-annual maintenance for external components such as is provided by our Complete Care plans which are described in this web document.

Complete Care Service Plans (PDF)

Content added 17 Jan 2024:

The Device Settings app utility on the Mesa 4 and Mesa Pro provide options for disabling power to docking pins, USB ports, and/or RS-232 port to help slow potential corrosion of the exposed metal parts. USB ports may become disabled automatically while wet and enable again when dry.

Content added or updated 2 Oct 2020:

The Mesa 3 Windows model has an electrical circuit that allows power to be turned off and on to the docking pins to help prevent potential accelerated corrosion. The USB and HDMI docking pins are always powered whenever the Mesa 3 is docked. These options only control if the pins remain powered when the Mesa 3 is not docked. The default is USB pins are always powered. This is to allow the Mesa attachable keyboard to function. The default is HDMI pins are only powered when docked. This utility will be located on the Mesa 3 under C:\Program Files\Juniper Systems\M3AppDock.exe

Content added or updated 3 Feb 2020:

If additional protection is desired, an LPS2 / LPS3 lubricant gel, a nano-coating, or a similar substance could be applied to externally exposed metal components. Though applying this could reduce functionality of the ports/pins to which it is applied, so using wireless connection methods instead may be needed. Some examples of such substances are at the following web pages.

• https://www.itwprobrands.com/product/lps-2
• https://www.itwprobrands.com/product/lps-3
• http://www.neverwet.com/
• https://liquipel.com/pages/about-liquipel

If corrosion has already surfaced on your ports, there are a few items you will need to get the corrosion cleaned off.

1. Deoxit D5S-6 cleaner. This cleans, protects and lubricates electronic components. This cleaner is safe for metals and plastics.
2. Non-abrasive brush such as a tooth brush.
3. Plastic pics in case you need to clean where the brush can’t reach. These will be plastic versions of dentist picks.
4. Cotton swabs and/or microfiber cleaning cloth.
5. Canned Air.

Before starting the cleaning, make sure you unplug the power cord. Now shut down the device by powering it down completely. Once the handheld has been powered down and all the lights on the unit are off, remove the battery from the unit. Follow the steps below.

1. Spray Deoxit over the corroded area and let it sit for 10-20 seconds.
2. Start scrubbing the affected area if you can reach it with the brush, if you can’t use the picks.
3. While cleaning, continually remove the chunks or goop of corrosion with the cotton swabs or microfiber wipes.
4. Continue to spray more Deoxit as needed and repeat the above steps as needed.
5. Once the corrosion appears to be gone, use the canned air to clean and blow off excess Deoxit.
6. Once the Deoxit appears to be gone, let the device sit for several hours to dry. DO NOT use a heat gun to attempt to speed up the drying process. It will evaporate over time.

After waiting several hours, re-insert the battery and power on the device and test your ports to see if they work.

Previous article content from July 2012:

If the externally exposed hardware ports are not needed for any specific application, then they may be disabled to reduce pin voltages (which can accelerate the potential for corrosion). On the Allegro MX, the following Windows registry keys are examples of ways the ports could potentially be disabled.

[HKEY_LOCAL_MACHINE\Drivers\BuiltIn\Serial1]
"TransAlwaysOn"=dword:0
0= Transceiver is enabled/disabled when COM port opened or closed
1= Transceiver is always enabled. The default is 1 (always enabled)


[HKEY_LOCAL_MACHINE\Drivers\BuiltIn\Serial1]
“DtrAuto”=dword:1
0= Only apps set/clear DTR
1= COM driver clears DTR during COM_Close, if value doesn't exist then default is 1 (Apps set and clear)


[HKEY_LOCAL_MACHINE\Drivers\BuiltIn\OHCI]
“Dll”=String:”ohci2.dll”

Previous article content from Jan 2010:

Allegro CX and CE Ports and Pins Enhancement

When an older Allegro CX or CE Field PC is subjected to weather conditions that are near salt water, some components of the Allegro can begin corroding. The components that may experience corrosion are the following:

• COM port casing around the pins
• Jack screws next to the COM port
• Charge pins

Juniper Systems, Inc. has historically offered a retrofit for older Allegro CX and Allegro CE Field PCs that replaced the corroding parts with stainless steel parts, which were designed to significantly reduce these corrosion problems. Though USB ports of such design are not available (at the time of writing).

Normally, the part needed for this retrofit were stock items. There were two retrofit options available:

Please be aware that the retrofit was only available on the Allegro CE and Allegro CX Field PC models.

All Allegro MX and CX units manufactured after May 20, 2005 are equipped with the stainless steel COM ports, jack screws, and charge pins as a product standard. Other ports and pins are not available in stainless steel.

The Allegro CE/DOS and DOS units use different style COM port connectors. We were unable to locate any stainless steel port connectors for the Allegro CE/DOS and Allegro DOS units. However, the charge pins and jack screws could be used. This would have allowed a partial retrofit for CE/DOS units.

If you have questions, please contact us at 1 (435) 753-1881 or you can email our Customer Service Department as support@junipersys.com.