Go 520 y sd

Me ha dejdo un amigo un GO 520 para actualizar mapas y radares. Con el rollo ese del mes de abril del 2019 lo he puesto primero en el tomtom home (sin hacer copia antes, error mio) y lo ha actualizado, cosa en en un XL no lo hizo. Me puso el navcore 9541 y he puesto el 9510
Mi sorpresa ha sido que al poner un mapa en la SD (antes no la habia utilizado nunca) no la lee y borra el archivo ttgo.bif.
Aqui pongo el archivo ttgo.bif del gps.
[TomTomGo]
DeviceName=TomTom GO 520
DeviceVersionHW=GO 520
Device******Number=
DeviceUniqueID=
RamDiskVersion=20130404
BootLoaderVersion=55120
LinuxVersion=547200
ApplicationVersionVersionNumber=9510
ApplicationVersion=1234792.1
UserLanguage=Español
UserName=
LastConnectionTime=Never
GPSFirmwareVersion=GSW3.2.4TT_3.1.00.12-C35B1.02
.../...
CurrentMap=Iberia_1025_9386
CurrentMapVersion=1025.9386
Traffic=N
CurrentFuelpricesType=
CurrentFuelpricesTypeString=
CurrentFuelpricesLastFullUpdate=
ValueRatio=AlClOvA70ozWm3Xmgw==
Features=PlusOrRDSTMCTraffic,PlusSafetyCamerasDyna mic,PlusSafetyCamerasStatic,PlusFuelPrices,HDTraff ic,PlusTripReporting,OnDevicePayments,HidRemote,Ho meBackup,ASR,ASRCnC,TTS,TTSCompressed,TTSLoquendo7 00,PhotoViewer,PhotoJPGViewer,PhotoBMPViewer,Voice Browser,LinkVolumeToNoise,MapShare,Newyork,Itinera ry,Caymann,Durham,Leeway,Handsfree,PhoneFeatures,C arSymbol,TextureRendering,ExtraSounds,UserSkin,Ric hPOI,FrequentDestinations,PermanentMapCfg,RDSTMC,B luetooth,SDSlot,InternalFlash,Microphone,SMSSuppor ted,SettingsOverride,SDK,USBAccessories,MultipleMa ps,Traffic,MapOverlays,Documents,WarningSounds,Dan gerZonesCameras
UnsupportedFeatures=PlusDownloadDynamic,PlusDownlo adGeneral,PlusDownloadMap,PlusDownloadPOI,PlusDown loadScheme,PlusDownloadUpgrade,PlusDownloadVoice,P lusDownloadRingTone,PlusMessageNotification,PlusFo rceMessageNotification,PlusPushChannel,PlusTraffic ,PlusWeather,PlusEphemeris,PlusBuddies,PlusRoadCon ditions,PlusFuelPriceTimestamp,Hercules,HerculesTr affic,Oxford,TrackMe,GPRSEngine,VoiceRecording,TTS Uncompressed,TTSNuance51,MP3,IPOD,MusicPlayer,Game s,LinkVolumeToSpeed,ZeroVolumeSupported,CaymannAlw aysOn,MAC,DepartureAdvisor,RouteInfoBackToSummary, VehicleProfile,MapShareVehicleProfile,3DCarModels, InternalModem,Prague,HardDisk,ExternalModem,Keyboa rd,SupportKeyControl,SupportGetAMap,Work,WorkEnabl ed,WorkPromotion,WorkTuria,WorkMurcia,WorkBremen,W orkUsePlus,WorkStartUpPromotion,LiveServices,Simpl eMapBrowserButtonBar,HTTPActivation,AltDefaultCarS ymbol,ArrivalSounds
SupportedPatchTypes=3F
NrSupportedErrorTypes=138
UserPatchDatVersion=102
CompressedPatchVersion=200
MapServerPatchDatVersion=105
DeletedPoiDatVersion=200
ServerLineIndexDatVersion=102
ServerNameIndexDatVersion=102
MapShareSupportedProviders=243
CharacterSet=TTU
VehicleBrand=
VehicleModel=
VehicleOptions=

Algun experto me podria indicar el motivo por el que no lee la SD para mapas, si que poniendola en el tomtomhome la utiliza para el telefono.
Saludos