After placing the unpacked Navcore on device and resetting for 15s it does not announce no map found instead shows system information. First line says Build -N/A-. Does this mean navcore didn't load?

Forget the 15 seconds.
3.Swich on te device till the announcement "No map found"
Go further with 4. etc.

It does not say "No Map Found"

Forget no map found. If you switch on the device what screen your got.

Finally got it working with a smaller map. This one has no voices. Can I put larger map on SD card?

You have card content.
Put the card in the GPS .... then you can download the map you want with "TTActivator".
You can activate with "FastActivate" or "TTActivator".

[Please Register or Login to download file]

What else do I need on SD card? Navcore? ttgo.bif?
Do I need an installer to install navcore?
I'm sorry I can't seem to find answers to these questions in the forum.

You need some data on the card ... to activate the map.

nickalex wrote:You have card content.
Put the card in the GPS .... then you can download the map you want with "TTActivator".
You can activate with "FastActivate" or "TTActivator".

[Please Register or Login to download file]

I am a bit confused. I thought TTActivator was for newer devices (Nav3) This unit is a GO-720

Ok I have an SD card that has everything I need on it except the navcore is an older version. It seems that it has trouble finding the satellites. How do I go about writing the proper navcore to the SD card without losing everything else?

Finally have had some success with unit.Have installed navcore 9.541 on internal drive and Map 1105_11819.(1G).
Then installed Map 1105_11753 on SD card.
It seemed that no voices came with that installation so was able to add one English(US) voice to internal. This gave a voice but not able to read street names since it is not a computer voice. Have tried to install standard voices but still only have one voice choice(Susan).
What do I need to do to add other computer voices? Have switched maps ok but not voices

The standard voices are here

Looking for update of 1105_11753. I think it may be 1140_12533. Does this look right? 1105 was north America. 1140 map is USA Canada. Where is the best place to download? On initial try it came up with a site that was not in English. Tried to change to English but didn't seem to work.

turk wrote:Looking for update of 1105_11753. I think it may be 1140_12533. Does this look right? 1105 was north America. 1140 map is USA Canada. Where is the best place to download? On initial try it came up with a site that was not in English. Tried to change to English but didn't seem to work.

see here and yes, you can use the latest 1140 maps tomtom-tools/tomtom-map-download-directly-tomtom-using-ttactivator-t23206-15.html

Yes, as all nav2 devices can use nav3 maps, for your Go 720 the last USA_Canada map (with known metacode) is a nav3 one : USA_Canada 1140_12533.
Sizing 4350,2Mb, you will need a SDHC card, 8Gb up to 32Gb.