hello ,

the drive doesn't spin at all , the PCB looks fine , no burn marks ..

suspecting several components ,


copmponent 1 shorted
copmponent 2 ~54K OHM
copmponent 3 ~84K OHM
copmponent 4 ~61K OHM


thank you

Hi, generally not useful measuring ohms on capacitors (3 & 4).

I think 1 is the 12v TVS Diode and 2 is the 5v TVS Diode, so try testing as diodes

but I am no HDD Guru

But you're the man with the impressive Flash drive collection Can you tell I'm envious?

Let me help out a little here: Component 1 is an inductor, not a TVS, and measuring as "shorted" for DC resistance is therefore correct. This drive doesn't use the +12V power rail at all, so there is actually no +12V TVS. Component 2 is indeed the +5V TVS, and based on that reading, it does not appear shorted so I'm not suspicious of that. Due to other components across the +5V supply, it's normal to measure some resistance. As you said, components 3 & 4 are capacitors and are not shorted, so beyond that, DC resistance measurements are of no real value in this situation.

If the OP explains the history to this situation i.e ask the owner to explain what events led up to the current problem, it might be possible to make further suggestions, but no guarantee. Someone with the time to spend on this, might volunteer to walk the OP through some voltage measurements, but again no guarantee.

thanks Vulcan, I really must do some proper electronics theory, instead of just hacking. Thanks for explaining it.

Bought another 7 flash drives today Website should have a bit of content in around a week.

Measure Vcore and Vio.

_________________
A backup a day keeps DR away.

thank you again for your help ..

the measurements are like the following
unit DC volts
a 5.11
b 3.31
c 3.31
d 3.31
e 3.31
f 4.1

g 5.14
h 0.71
i 0.71
j 0.71
k 0.71
l 5.13

thank you again

The two 6-pin "642h" components appear to be MOSFETs.

The "a-f" device appears to be the pass transistor in a linear regulator controlled by the TLS2502B motor controller. The Vio supply (+3.3V) is functioning correctly.

However the readings on the "g-j" device suggest that the Vcore supply has a problem. This appears to be pointing to the TLS2502B as the culprit. However, I would measure the voltage at the output of the 4R7 coil, and I would also measure the resistance of the coil, and the resistance of the output filter capacitor.

If you have a CRO, then check for PWM pulses at the gate of the MOSFET (the "g" pin).

_________________
A backup a day keeps DR away.

Bad TLS2502 is most likely. If heads are stuck on platter, drive won't spin up either.

_________________
http://www.datasaversllc.com

thank you all for your time ,, i will do more tests adnd measures , and report them ..