In the unit Garmin folder, the following detail map names will work: gmapprom.img ; gmapprom1.img & gmapsupp.img. A possibility that gmapoem.img maybe will work in there too.
In the SD Garmin folder, only gmapsupp.img will work for sure, but after recent US/EU fw update, gmapsup1.img also works in the sd. Maybe it will work also if you have TH device & fw.
If your TSM map still won't work, check it with [Only registered and activated users can see links. ] for errors and correct unlocking. Or just run an unlocker on it to be sure it's unlocked, [Only registered and activated users can see links. ] or [Only registered and activated users can see links. ].
BTW, best to have 'unofficial' unlocked maps on an sd imo, that way if things go wrong just take out the card and the unit will function normally.
To check your fw version: Tools > Settings > System > About. There you can see what fw version is loaded and check that against the latest version available from Garmin....... I've never had any difficulties loading these maps into my 1490T and I'm wondering if the problem stems from the fact that the 205 was bought in Thailand (presumably has Thai firmware) and the 1490T was bought in the UK?
A side issue is that when I try to update the 205 firmware I get the message "firmware is up to date" even though the device is 2 yrs old and has never been updated.
Search is your friend, all the info i've given above is available on this forum. Here's a good place to start: [Only registered and activated users can see links. ], and all the tools are here: [Only registered and activated users can see links. ]. Good luck!.......... Can anyone throw any light on these issues? - I apologize if this isn't the correct forum but I have searched this website for related threads and can find none! .....