Garmin GPSMAP 740s Display Now Mirror Image

Electrical and electronic topics for small boats
Jefecinco
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Joined: Fri Oct 09, 2015 6:35 pm
Location: Gulf Shores, AL

Garmin GPSMAP 740s Display Now Mirror Image

Postby Jefecinco » Thu Apr 18, 2019 11:14 am

Yesterday we took our 190 Montauk out for the first time in over a year. We found the MFD screen was displaying the menus in a mirror image or backward. The touchscreen was not responsive to most selections. After a lot of useless attempts to use the MFD it did display some sonar features and I could read what appeared to be the correct depth and boat speed in split screen format with a map too small to be useful. The mapping chip was not installed but I believe the standard US mapping should have been available without the optional charting chip.

The Garmin is nine years old so I can accept replacing it with a current unit but obviously prefer to get it working properly.

We keep the Montauk in a dry stack marina so access is not easy but I'm willing to try any "field fixes" recommended. Meanwhile I'm looking for a system reboot sequence.
Butch

ConB
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Location: Suttons Bay, MI

Re: Garmin GPSMAP 740s Problem

Postby ConB » Thu Apr 18, 2019 9:10 pm

Butch, looking at the Garmin on line manual for your unit I see on page 84 is a touch screen recalibration. Maybe that is the problem.

I was in your neighborhood last New Years and my car Garmin needed a reset to get it working right. Found how to in the on line manual.

Con
!987 Outrage 18 / 2011 Yamaha F150
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Jefecinco
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Joined: Fri Oct 09, 2015 6:35 pm
Location: Gulf Shores, AL

Re: Garmin GPSMAP 740s Problem

Postby Jefecinco » Fri Apr 19, 2019 9:55 am

Con - Thanks for the comment. Screen calibration is my next step. There is also a procedure to reset the unit to the factory settings and that is my fallback procedure. I would not hesitate to do the reset but it will erase all my trails and way points. There is also a procedure to save all the trails and way points to a thumb drive for later installation. Experience tells me to try the easiest things first.

I tried calling Garmin yesterday but the minimum hold time was three hours and eighteen minutes. I assumed I had misheard so I called their non-toll free number and heard the same message. I then used the "chat line" which was much quicker but a little frustrating to use due to the message lag times. The first recommendation was to replace the unit which is nine years old. The technician(?) said she had never heard of a reverse screen problem. Neither had I.
Butch

jimh
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Re: Garmin GPSMAP 740s Display Now Mirror Image

Postby jimh » Fri Apr 19, 2019 11:26 am

I can't say I have seen a problem with a display spontaneously going into a mirror image (reversal of left-right scan), but I have heard of such strange behavior occurring. I don't have any insight into the mechanism for that to occur.

As already mentioned, in a situation like this the best (and perhaps only) option is to force a reset to initial factory settings.

To force a device into a non-standard start-up mode of operation, the usual procedure is for certain physical buttons on the device controls to be pushed and held down before any power is applied to the device. In this way, when the device gets power it detects the button presses and branches into a different path for starting. There may be more than one option for a special start mode. My Lowrance device offers two paths. One resets everything to out-of-the-box factory state. The other preserves some stored data such as waypoints.

The circumstances when it will be desired to branch into a special start mode are hard to predict, and the ability of the operator to remember all the details of every device he owns is limited. For this reason, I have printed the instructions for my device (Lowrance HDS-8), and taped those instructions on the inside of the sun cover for the device. This allows me to be able to have that information at hand if I am out in the boat and not connected to the internet, don't have the printed manual handy, or need to get the device working again in a hurry.

For some devices, these methods of start-up to branch into non-standard configurations are described in the owner's guide, but for other devices you have to rely on insider knowledge. Such insider knowledge is often shared on the web among enthusiasts.

Jefecinco
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Location: Gulf Shores, AL

Re: Garmin GPSMAP 740s Display Now Mirror Image

Postby Jefecinco » Thu Apr 25, 2019 3:04 pm

Good news. Went to the marina and performed a "Screen Calibration". It's easy. Turn on the power and immediately place a finger on the screen and hold it there until the unit screen comes on. The unit now functions as before.

Thanks to all for the advice.
Butch

Jefecinco
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Joined: Fri Oct 09, 2015 6:35 pm
Location: Gulf Shores, AL

Re: Garmin GPSMAP 740s Display Now Mirror Image

Postby Jefecinco » Thu May 09, 2019 9:58 am

I took the boat out a couple of days ago for an all day fishing trip. Before leaving the marina I installed the 2015) Garmin updates for the GPSMap 740s display. Everything looked normal.

Shortly after getting underway the mirror image problem recurred. The map was not affected but the text labels were reversed.

In a few moments the [display] self corrected. This fault and self correction continued to recur every couple of minutes for about an hour. After that the [display] operated normally for the remainder of the outing. In sounder or fish-finder mode the unit operated normally.

This problem is more of an irritation than anything, but it makes me doubt the reliability of the Garmin GPSMap 740s.

I plan to continue using the [Garmin GPSMap 740s] until a more serious problem presents. I may try reinstalling the G2 mapping card data. Or, perhaps I'll leave the [Garmin GPSMap 740s] alone unless there is a recurrence.
Butch

jimh
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Re: Garmin GPSMAP 740s Display Now Mirror Image

Postby jimh » Fri May 10, 2019 9:52 am

On a GARMIN support forum I found this thread on the same problem:

https://forums.garmin.com/forum/into-sp ... aa/157691-

Jefecinco
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Re: Garmin GPSMAP 740s Display Now Mirror Image

Postby Jefecinco » Fri May 10, 2019 10:15 am

Jim - Thank you. After a few hours of web searches I found nothing about "image mirroring(?)". Your search skills exceed mine, by far. I guess I have to bite the bullet and buy a new GPS. So far I'm in no hurry.
Butch

Jefecinco
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Joined: Fri Oct 09, 2015 6:35 pm
Location: Gulf Shores, AL

Re: Garmin GPSMAP 740s Display Now Mirror Image

Postby Jefecinco » Fri May 31, 2019 9:48 am

The Garmin problems we were experiencing made me doubt the unit's reliability. Earlier this week we used the boat again and the Garmin seems to have finally died. When turned on the screen showed only horizontal lines which were motionless. After a few repeat tries to get the unit to function by turning it off and on I gave up.

I'll be replacing the unit with a new 9 inch MFD. I'm leaning toward Simrad or Lowrance. I like that some models will accept input from the full array of SmartCraft data points. I have a lot of homework to do before buying.
Butch