why won't (new) SD card work on my phone?

A

AC Question

Let me begin from when I bought my new phone it was a BLU studio X8 HD Android version 4.4.2 Kitkat it's Build number Modem_BLU_S530_V12_GENERIC 01-07-2016 14:11 Kernel Version 3.4.67.

I had an old 2GB memory card for as long as I can remember so I inserted into the phone before I booted it for the first time(don't know If that was a bad idea) the memory card worked fine, flawless actully if it wasn't for it's tiny size.

After a few days I noticed that the phone treats the memory card as if it is internal storge and the phone storge as if it is external storge mabey because I put in the card before booting the phone for the first time, either way I didn't have a problem with that.

It wasn't untill two months later that I decided to buy a new card, I didn't want anything huge so I setteld for a 16GB Memory card made by Advance i bought from a local shop it didn't say where it was made or which class it was(I know it was a bad idea but...) So, I went home and unmounted my old 2GB card, removed it and inserted my new card and mounted it.

All went well the phone recognized the card so, I statred testing it first I sent a bunch of videos from another phone to my phone, the videos were sent they showed on my phone but when I play them with default video player it says "Can't play video" I try to play them with Vlc, the video either opens but doesn't play and it's lenght is 00:00:00 stays for three seconds then closes, it opens but doesn't play and it's lenght is something ridiculous like 16:56:04 and doesn't close or it plays fine the first time and doesn't play ever again and in all cases the file of the video becomes undeletable as I try to delete it it says "no premission to delete" that is by it's self makes the card almost useless. so, I try another diffrent type of files.

PDF the pdf opens fine no problem but when I send it to card it says "corrupted PDF file" another let down.

I try photos I send a bounch from my computer to the card through USB, when I search for them in the phone they are no where to be found so, I search for them through writing the name of the file, I find but when I open them is says "no thumbnail to be shown" and I can't delete them.

And to top it all I accidentally opend the camera and was shocked by it telling me that the SD Card Storge is full and I should clear some space or change default storge location. I gave the card to my friend for the day and the next day he surprised me by teling me that the Card worked fine in his phone (His phone was a Samsung J5) I didn't know what to do, so I returnd the card to the shop from where I bought and thankfully got my money back (by the way I reinserted my old 2Gb card and it worked fine thankfully).

After a while (2 weeks) a decided to buy another card this time it was a Toshiba 16GB class 10 Card it was made in Taiwan(great country by the way).

Again I removed my old card and inserted and mounted my new card, I copied a few PDFs, mp3s, videos and photos from the phone storge to the card, they worked fine except for the videos some would work and rest won't and those that work would only play the first time and never again.

So, I copied the rest of PDFs and Mp3s and Photos from my computer to the card, did it work fine? the answer is no, when I searched for the files some of them I found but won't work and most of them are no where to be found, I knew they were there because the folder is there but not the files. so I unmount the card then remount it but the folders disappear and the folder called "Lost.Dir" is filled by files and has the exact same size as the file that are missing (goodthing I made a copy of the files before cutting the other copy) when I try to copy other files the same thing would happen again.

I gave the Card to my friend and he tested it and you know what happened?, it worked fine with no problem. so, I don't know if the problem is with my phone (I don't think so because then why would the 2GB card work) or if my friend is lying (he wont. right?).

I searched everywhere online for a solution but to no avail.

Some said to format the card but when I format it in the phone the problem is not solved and when i try to format it in my computer it says that it's write protected (it's not), some said to erase it using cmd, that didn't work asthe task won't complete.

So finly I decided to post my problem here as a last resort so is my problem fixable? or will I have to live my life with the 2GB card?

I hope I covered everthing and didn't make it too long (sorry if it is)

Thanks in advance for any help