When we are coming to the topic of flash data recovery, it’s very necessary for us to have a general view of the typical failures of flash drives such as the SD, CF, SM ,MMC, XD, USB Pendrive, MemoryStick, etc.

It’s believed 90% of flash drives’ failures are due to corruption in the lookup tables which convert logical addresses (what your computer sees) to physical addresses (what the controller sees). Other failures are usually caused by controller failures, power surges, and worn or broken solder joints.

NAND memory has many quarks.

Lookup tables

Lookup table is an array or matrix of data that contains items that are searched. Lookup tables may be arranged as key-value pairs, where the keys are the data items being searched (looked up) and the values are either the actual data or pointers to where the data are located. Sometimes, lookup tables contain only data items (just values, not key-value pairs).



Weak Solder Joints


Hacked USB Flash Drives

Broken USB Connector

If the USB connector was broken off the USB Flash drive you can recover the data by repairing the trace using a conductive pen.

1. Use a set of tweezers to place whats left of the trace on its original path
2. Expose the copper at the end of the broken trace by scraping off the sealant with an XACTO knife
3. Use a conductive solder pen (available online or at radio shack) and carefully recreate the broken trace.
4. Let the paste dry, then use a needle or XACTO knife to scrape off any excess.
5. Make sure the trace is repaired by doing a continuity test with a multi-meter from the pad to the end of the trace.
6. Quickly solder the old USB connector back on the board. The paste left by the pen won’t hold up to heat for very long, don’t spend too much time trying to make the joint perfect.
7. CAREFULLY connect the flash drive to your computer, the connection is VERY weak and easily broken. I recommend connecting the drive to a USB extension cable for easier insertion.

Bad Surface Mounts


As for flash data Recovery,  the NAND memory chip must be removed and read with an external reader, then the lookup table is reconstructed to retrieve your data.

As for flash data recovery tools, there are not many good ones to recommend, so far ACE flash data recovery tool and the coming flash doctor can be worth a try. There are many data recovery providers who have their own tools for this kind of recovery, but according to customers, the result is not ideal!

This article idea is very interesting and written by Jeremy Brock