HDD GURU FORUMS

Hi there,

We received this not detected USB 2.0 flash drive for data recovery and have serious reasons to think that the resistor at location R25 could be missing.
Does anyone have this board model and could take a good quality picture of the resistor, or tell us the resistance value?


Circuit board:

Code:

C20V-2.0-SM3257EN-L48-2L
-1F (LGA TSOP)-1.0 2011-02-25

Controller: Silicon Motion SM3257EN


Reasons for us to think that a resistor at R25 is missing:

• Under the microscope, the resistor at R25 appears having been torn off: the weld is not smooth but abrupt shaped.
• The customer told us the flash drive was intermittently working during some time when he pressed on it.
• Another picture of the same circuit shows the presence of a resistor at R25: http://www.datasheetcafe.com/wp-content ... EN-DI1.gif
  Unfortunately it is too blurry to allow reading the resistor value (if printed on it).
• There are no other apparent damage and replacing the USB connector does not bring anything.

On the shell, one cannot read the brand name anymore and the customer cannot remember it, but likely a popular model from Emtec or so.

Thank you for your kind help.

The resistor appears to be in series with the +5V supply. Typically it would be 2R2 (2.2 ohm) or 1 ohm. You could use a wire link or a fuse, but first verify that there is no short between ground and the load side of the resistor.

See pin #37.

http://www.datasheetcafe.com/sm3257-datasheet-pdf/

http://j5d2v7d7.stackpathcdn.com/wp-content/uploads/2015/10/SM3257-datasheet.gif