if I only talk about device no.2 as it is the least dealt with
1. update through Garmin Express - success updating (on screen) but does only show logo when starting, then shuts off
2. updated with updater.exe using 172201000410.rgn (converted Nuvi24x725x7,China_GCDfileonly__410.gcd) - still same result, successful update but does not show anything but the logo.
this is where I stand with device two
No luck using Asian launcher tool as it does not find the GPS in pre-boot
on top of that, I seem to not be able to use the same PC to update the GPS twice - no communication seccond time (I have now used 4 different PC's for these PC's (2 updates each)