128gb Ultra SDXC and MobileMate reader issues

Memory Cards SD | microSD | CFast | CFexpress | CompactFlash
1

I bought a 128gb Ultra SDXC sd card along with a MobileMate reader from an official retailer a few months ago.

After inserting the reader windows would not pickup on the card itself and only the reader. After few reinserts it worked. Formatting was awfully slow. I then used the device on another computer and even my TV with exact same issue. The drive would not show even after inserting it multiple times.

Once its working the write speeds are 8mb/s. The reader was getting hot so I decided to purchase the same reader and the exact same issue is happening.

After inserting the drive it puts my computers into a state of distress with explorer crashing at times and the entire system slowing down.

The previous reader had burn marks on the internal copper bridges.

Right now I am trying to format the drive and after 15 mins I am at 3% (exfat) this reader also gets hot. Inserted in 3.1 slots, Windows 11.

2

Hi @Cosmo1

Have you checked our knowledge base articles?
(Get Support for Your SSDs and Flash Products | SanDisk)

Have you opened a Support Case?
If not, contact SanDisk Technical Support for assistance.
(Contact Support | SanDisk)

3

Your SD card is likely faulty or fake. It’s causing slow speeds, system crashes, and overheating your readers. The burn marks on the first reader suggest the card is drawing too much power. Try testing it with H2testw to check if it’s real. If the problems continue on different devices, return or replace the card.

4

You have a counterfeit card as the Ultra is much faster.