This page was last updated:  10/21/10
 

If you are considering an upgrade to your instrument you have two options. First, you may return it to the factory or one of the Cambridge Aero Service Dealers.

The GPS-NAV is not user upgradeable.  It must be returned to a Service Dealer or the factory for upgrade.  The second option is to do the upgrade yourself. We have given a brief overview of the upgrades below for your review. If you are comfortable using hand tools and are technologically inclined, you may do them yourself and save time. Be sure to ground yourself before starting this upgrade as there are static sensitive components within the instrument. Please remember though, Cambridge Aero cannot be held responsible for damage that may be done to the instrument by the customer.

302
303
S-NAV Version 7.X
S-NAV Version 8.X
L-NAV Version 5.X
GPS-NAV Flight Recorder Version 6.X
GPS-NAV Display Version 5.X

S-NAV Version 7.X: Single Seat
S-NAV Version 8.X: Two Seat

The changes listed below apply to both versions. Each version contains a different revision of the digital PC board, this is why there are two PC board links shown below.

Features:

See the Version 7/8 Users Manual.

Known Problems with V7.2/8.2:

	If the S-NAV is turned off and on again during flight, the timer resets.
	If the S-NAV is turned off and on again during flight, the MaCready setting resets to zero.
	If the S-NAV is turned off and on again during flight, the altitude set in the Temperature/Altitude screen (used in computing True Airspeed) is not preserved.
	At sink rates above 20 knots, (10 M/S), the meter "wraps around" and shows lift.
	The Climb Averager and Netto Averager display sink in excess of 10 knots (10 M/S)  as -x.x.

The changes below were made to Version 7.2/8.2, bringing it up to 7.3/8.3

	The known problems with V7.2/8.2 were corrected.
	Minimum G and Maximum G can now be reset with the Up and Down Keys (with G-Meter option installed).
	The unit now goes to the main flying screen upon loss of fix or loss of GPS data.
	Improved the thermal statistics algorithm (Chip Garner).

Known Problems with Versions 7.3/8.3

	When altitude difference is used, and the distance to go is 0.0, the altitude difference will show zero. It should show negative goal altitude if you are on the ground at the turnpoint.
	Occasional unwanted audio squawks.
	Occasional display of unreasonably high vector winds.
	Resetting of elapsed time in some maneuvers.
	Low Backup Battery warning did not work.
	Occasional unwarranted display of spoiler/gear-up warnings.
	Scrolling acceleration reduced usefulness of meter test screen.
	A/2 reading was not shown in Altitude Cal screen.
	Average G should not have been shown in the G-Meter indicator screen.

Added Features to versions 7.5/8.5

	Improved thermal statistics.
	Audio 1,2 and 3:     Audio 1: Long pulse-width tone for all climb rates.     Audio 2: Long pulse-width tone for rates higher than McCready.                   Short pulse-width tone for climb rates lower than McCready.     Audio 3: Same as Audio 1 except that speed-up and slow-down tones are reversed.
	Averager and Average Neto get reset to current value on climb/cruise transitions.
	GPS detected circling can be used for climb/cruise transitions.
	Home screen now shows altitude instead of altitude required.
	NEMA checksums modified to allow connection of a Filser LX-400.

Version X.4 was never released. The above list of changes that were made to Version X.3 have been accumulated over the Summer and are based on feedback from our customers, as well as  extensive testing done by Cambridge Engineers.

Please see the L-NAV page for S-NAV upgrade pricing. We can ship you the Upgrade Kit directly or you may return the S-NAV to a Service Dealer or to the Factory for the upgrade.

S-NAV 7.x UPGRADE INSTRUCTIONS

Click here to view the single seat versions of the PC Board.

1. Loosen the screws holding the top cover in place.
2. Remove the screw on top of the cover.
3. Remove the top cover.
4. Turn S-NAV upside down on a soft surface.
5. Remove all screws on the bottom panel.
6. Gently move bottom panel off to one side.
7. Remove any mounting standoffs that secure the bottom board to the middle pc board.
8. Gently pull the bottom board free of the middle board.
9. Disconnect the ribbon cable securing the bottom board to the display.
10. Locate the EPROM to be replaced (using diagram above).
11. Note the orientation of the EPROM before you remove it.
12. Gently pry the EPROM from its socket.
13. Insert the EPROM, note the orientation of the notch.
14. Reconnect the display ribbon cable.
15. Press bottom board onto middle board making certain all the pins are seated properly in the socket on the middle board.
16. Reinstall the standoffs removed in step 7.
17. Place the speaker panel back onto the standoffs.
18. Reinstall all the screws on the bottom panel.
19. Reinstall the top cover.
20. Connect the S-NAV to power and turn it on. You should see a message "UPGRADING" for a moment. The S-NAV will go to its barograph screen and will work normally.

S-NAV 8.x UPGRADE INSTRUCTIONS

Click here to view the two seat versions of the PC Board.

1. Loosen the screws holding the top cover in place.
2. Remove the screw on top of the cover.
3. Remove the top cover.
4. Turn S-NAV upside down on a soft surface.
5. Remove all screws on the bottom panel.
6. Gently move bottom panel off to one side.
7. Remove any mounting standoffs that secure the bottom board to the middle pc board.
8. Gently pull the bottom board free of the middle board.
9. Disconnect the ribbon cable securing the bottom board to the display.
10. Locate the EPROM to be replaced (using diagram above).
11. Note the orientation of the EPROM before you remove it.
12. Gently pry the EPROM from its socket.
13. Insert the EPROM, note the orientation of the notch.
14. Make certain the EPROM is inserted EXACTLY as noted in step 11. The EPROM must be inserted in the left side of the socket.
15. Reconnect the display ribbon cable.
16. Press bottom board onto middle board making certain all the pins are seated properly in the socket on the middle board.
17. Reinstall the standoffs removed in step 7.
18. Place the speaker panel back onto the standoffs.
19. Reinstall all the screws on the bottom panel.
20. Reinstall the top cover.
21. Connect the S-NAV to power and turn it on. You should see a message "UPGRADING" for a moment. The S-NAV will go to its barograph screen and will work normally.

L-NAV Version 5.X

Features:

See the Version 5 Users Manual.

Known Problems with V5.2:

	When the L-NAV is used with a Repeater and GPS, it will sometimes "lock up" after about 4 hours of flight.
	If the L-NAV is turned off and on again during flight,  the elapsed time counter resets.
	If the L-NAV is turned off and on again during flight, the MaCready setting resets to zero.
	If the L-NAV is turned off and on again during flight, the altitude set in the Temperature/Altitude screen (used in computing True Airspeed) is not preserved.
	At sink rates above 20 knots, (10 M/S), the meter "wraps around" and shows lift.
	The Climb Averager and Netto Averager display sink in excess of 10 knots (10 M/S) as -x.x.

The changes below were made to Version 5.2, bringing it up to V5.3.

	The known problems with V5.2 were corrected.
	Minimum G and Maximum G can now be reset with the Up and Down Keys (with G-Meter option installed).
	The unit now goes to the main flying screen upon loss of fix or loss of GPS data.
	Improved the thermal statistics algorithm (Chip Garner).

Known Problems with V5.3

In some L-NAV hardware, the altimeter reads very high altitude while descending through ten thousand feet.  This causes wild variometer and wind readings.

The changes below were made to Version 5.3, bringing it up to V5.4.

Fixed known problems with V5.3.

Known Problems with V5.4

When altitude difference is used, and the distance to go is 0.0, the altitude difference will show zero. It should show negative goal altitude if you are on the ground at the turnpoint.

Changes  to be made to Version 5.4 to bring it to version 5.6

	Fix the known problems with 5.4
	Occasional display of unreasonably high vector winds.
	Resetting of elapsed time in some maneuvers.
	Scrolling acceleration reduced usefulness of meter test screen.
	Power cycle at high altitudes could cause temporary errors in the altitude reading.
	Average G should not have been shown in the G-Meter indicator screen.

Features added to Version 5.6

	Improved thermal statistics.
	Audio 1,2 and 3:     Audio 1: Long pulse-width tone for all climb rates.     Audio 2: Long pulse-width tone for rates higher than McCready.                   Short pulse-width tone for climb rates lower than McCready.     Audio 3: Same as Audio 2 except that speed-up and slow-down tones are reversed.
	Averager and Average Neto get reset to current value on climb/cruise transitions.
	GPS detected circling can be used for climb/cruise transitions.
	Home screen now shows altitude instead of altitude required.
	NEMA checksums modified to allow connection of a Filser LX-400.
	Added Max McCready feature.

Version 5.5 was never released. The above list of changes that were made to Version 5.4 have been accumulated over the Summer and are based on feedback from our customers, as well as  extensive testing done by Cambridge Engineers.

L-NAV Version 5.7

In addition to the changes in the firmware, version 5.7 also makes possible the measurement of outside air temperature using an outside air temp probe. This feature must be installed at the factory or at a Cambridge Service Dealer. Please see the L-NAV page for further details.

L-NAV Version 5.8

Please see the L-NAV page for further details.

L-NAV UPGRADE INSTRUCTIONS

Click here to view the printed circuit board for the L-NAV showing the location of the device to be replaced.

1. Remove Cover -- Remove top screw, loosen or remove the remaining six screws.
2. Carefully remove the old ROM lift under the edge (between the rows of pins), and pry it gently out of its socket.
3. Install the new ROM Be sure the notch in the EPROM is oriented to the notch in the socket. Make sure all the pins are in the socket and not bent under after insertion.
4. Perform a Reset Hold in the GO button while turning on the L-NAV. You will see the Configure screen. Go two screens to the left, you will see Defaults. Press GO. The L-NAV will reset and you will see the new revision number.
5. Replace the L-NAV cover, making sure the silicone tubing is not pinched between the cover and the PC Board.

GPS-NAV Display Version  5.X (all languages)

	Fixed a bug that allowed erroneous Restricted, In Sector, and GPS Fail messages to appear in V5.2.
	Added the display of pressure altitude to the screen just above the main flying screen.
	In the French version only, improved the French translation as suggested by Christian Stuck.

GPS-NAV DISPLAY UPGRADE

Click here to view the GPS-NAV Display printed circuit board.

1. Remove the 4 screws from the back of the display.
2. Lift the back of the display off of the front bezel.
3. Gently pull the display PC board from the rear of the display.
4. On the back of the display you will see a square 44 pin microprocessor (see above photograph). Note the orientation of the microprocessor. You will see one corner that is angled. You need to gently remove this with a small jewelers type screwdriver or other small tool. Make sure to pry it out from both corners so that the socket is not damaged.
5. Place the new microprocessor in the socket of the display PC board. Be certain the device is reinserted the same way it was found . Gently press it into the socket, it should sit flush with the socket.
6. Reassemble the display. If the display does not look correct once its back together, remove the screws and separate the two halves of the display to reposition the two pink rubber contact strips. Reassemble the display. This should correct the problem. if not try again,  it may take a few tries.
   

GPS-NAV Flight Recorder

Version 6.0 contains substantial improvements to the Flight Recorder. The most notable is the ability to output pressure altitude data from the GPS-NAV to provide altitude based on GPS-NAV Barograph sensor. Allows entry of QNH so "real" pressure altitude is displayed. To view the features of this new version click here.

Although the Flight Recorder may be accessed through the removal of the cover plate (Model 25) or antenna (Model 20) to replace the internal back-up battery (power must be connected to Flight Recorder before removal of battery), the EPROM cannot be replaced without completely disassembling the unit. Due to the loss of security when this in done, the Flight Recorder must be returned to the factory or to a Cambridge Aero Service Dealer for upgrading.

Due to a bug in the Version 5.4 firmware, we have had to revise the GPS-NAV Flight Recorder firmware. During Pocket-NAV operation, the GPS-NAV will stop transmitting NMEA data to the L-Nav and to the Pocket-NAV for up to 45 seconds. A GPS Display and Pocket-NAV must be connected to the FR for this to happen. Sometimes the outage is long enough to cause the L-Nav and/or Pocket-NAV to display "GPS-OFF". If you are flying with only one of the displays connected to the FR this bug will not happen.

Starting with Version 5.4, the GPS-NAV Flight Recorder includes the IGC required "Event Marker" as well as Pocket-NAV compatibility.

Back to Top