EOS Rebel T7 won't turn on properly with old SD card, OK with new SD card

[Jaysonwrd]

I have recently gotten a new sd card for my camera, i still have my old one that previously was working the day of that i got the new sd card the next day after using the new sd card i went to put the old one back in which is still fairly new my camera doesnt turn on right away, i have to turn it off take out the battery then plug it back in and itll "turn on" a rapid flashing led flashes then slows down but nothing pops up on my screen nothing works but the camera is on just the only thing that works is the built in flash. the built in flash will go up when i click the button but the screen doesnt turn on nor does it take pictures, but when i put the new sd card in the camera it acts perfectly fine.... does anyone know what can be the problem? 

[stevet1]

Jaysonwa4d,

It so7nds l8ke your card may have gotten corrupted somehow. It probably would be best if you could reformat your old card in the camera.

If you can't re-format it, you should probably throw it out.

Steve  Thomas

[Waddizzle]

The Rebel T7 is a part of the EOS xxxxD family of entry level cameras, which seem to be a bit finicky when it comes to memory cards.  

For best results you should follow the above advice to format your memory card in the camera, with “low level” option enabled, prior to first use. This is a best practice for any camera that uses SD cards.  

I would add the caveats that pertain to your family of cameras. Stick to only using SDHC cards, 32GB or less.  For whatever reason, these models will frequently report card errors with SDXC cards, 64GB and larger.  

Finally, never use the micro-SD cards that need a plastic adapter. They are not included in the card types recommended by Canon.