Looking likely there's flash damage. However let's try some other things with SD card. Also what exactly happened to it? I know you said it bricked while using GarminExpress but can you give any more info, such as what was being updated, the detail map, firmware or other files at the time? Was the update interrupted or did it start bootlooping after properly disconnecting from GE?

Meanwhile, see if it can even recognize an SD and read from it by trying to dump it's NV. Read this: [Only registered and activated users can see links. ]. Command for your 1490 is "rrgn,41,1:/41.bin" as it's an older device. Let's try to dump a couple of other regions too, firmware regions 14 and 127, so make your update.txt file with these commands:
Code:
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Same as with flashing using Updater.exe, make sure the device is completely off by holding the power button down for 10 - 30 seconds to force it off, then insert the microSD and turn it on again. If it works 'Loader' will show on the screen and it won't bootloop until the flash finishes.