HDD GURU FORUMS

Hello,
Does anyone know what is that? It has NL on it, nothing more.

Hi, a pic of whole board can help to deduce what component could be in that part of circuit.

SMDs are marked with a marking code, so you would google for something like:
SMD Marking code "NL"

results like:

http://www.s-manuals.com/smd/nl
http://www.josvandijken.nl/smd_codes.php

Once you have a candidate you would verify by looking at the circuit/schematics of other available units and see if it makes sense.

As HaQue has said, context would have been helpful, but I suspect that the part is a 3.3V LDO regulator. I believe it provides a 3.3V supply for the adjacent MSP430 power sequencer/controller. ISTR that the series resistors for Vin and Vout are 10 ohms. If the output is low, then I would be testing the MSP430 for shorts.

Pictures attached. It was in the circled area. This little thing gets really hot in seconds. Black stains are from parker not burned.

Measure the resistances between ground and the 2.8V/3.3V test points.

Check that the 10 ohm resistors are not open or stressed.

I suspect that the MSP430 IC will be shorted to ground.

BTW, I'm guessing that the regulator was probably OK.

TLV70028DSER/T, Texas Instruments, 200mA, 2.8V, Low-IQ, LDO Regulator, marking NL, WSON-6:
http://www.ti.com/lit/ds/symlink/tlv700.pdf

Resistors are not open. Regulator is soldered.

@melvin, if you measure the resistance between ground and the "0.8V" test point, you will find that it is approximately 4 ohms. This means that the MSP430 microcontroller is shorted.

The following thread has a similar problem:

http://forum.hddguru.com/viewtopic.php?f=10&t=33908

Thank you fzabkar,
Yes, resistance is 4,5 ohms. Also the mentioned regulator is cold now, and test points show 0 or 0,8V so more work to be done here.