GPSrChive Discussion Forum

After performing the recently published Firmware v3.00 update on my GPSMAP 64sc, Garmin Express 6.12.0.0 soon indicated another update was available, this time for GPS Chipset Type M5 (1621) software version 4.40 (as of April 23, 2018).

So, naturally, I let Garmin Express install this update also and after restarting my GPSMAP 64sc, the unit went into a perpetual GPS Software Update cycle, where the update fails at about 24% every time, stops updating, then restarts the process again a few seconds later.

Of course, now my GPSMAP 64sc has zero Satellite reception capability.

I tries downgrading back to the previous Firmware 2.70, and while that was successful, my GPSMAP 64sc still does not receive any satellite signals.

Interestingly, while at Firmware 2.70, Garmin Express does not make any mention of the GPS Chipset Type M5 (1621) software version 4.40 update being available! And this software was published nearly a full year before the recent firmware version 3.00 was published.

Updating the GPSMAP 64sc to firmware 3.00 again does not resolve the issue.

A word of caution, if you see Garmin Express suggest this GPS Chipset type M5 update for your GPSMAP 64, I would suggest avoiding it like the plague!

Were you able to resolve that issue? I have a 64sc with f/w version 3.30 and yesterday Garmin Express was prompting me to update to the M5 chipset. Having not seen your post, I went ahead and updated. Thankfully, there was no problem and the device is working fine. Was Garmin able to help you?

Had to dig this one out of mothballs, dust it off, install some fresh batteries and test it again....

The 'About Page' does not show the current GPS Chipset version, nor does the test page that is displayed when holding the 'Enter' + 'Power' buttons when booting the device from a powered off state.

The GPS is working however, and has my position at about 13' estimated error.

Examining the GarminDevice.xml text document located written to the Garmin directory during each boot sequence indicates the unit is running GPS Chipset version 4.40.

Further inspection reveals that I apparently changed the file extension for the "006B162100.gcd" file located in the RemoteSW directory to "006B162100.zip" to prevent the device from re-processing it at every single boot.

Let us know which path you take and the results you have, please.

I too, couldn't see anything other than Software Version 3.30 on the 'About Page'. The device is otherwise working well and I enjoy using it from time to time. Lately, however, the many great features of the 66s and 66st make these two my go-to favourites. But it's nice to be nostalgic once in awhile, lol. Take care, stay safe.

Did you let it update the GPS Chipset Software?

Yes, I did. I saw the new software screen when I started it up but that quickly changed to the normal startup screen and then the 'Acquiring Satellites' screen. I've restarted it a number of times since and have not experienced what you did. All normal and working fine.

Good to hear!

Thank You.