Samsung HD103UJ fail with high pitch noise while head moves

[stef]

Hi,

my Samsung HD103UJ failed without any warnings. After power up the HDD makes a head-crash like noise
As soon as the head moves from the "park"-position to somewhere else, it stars to make a high pitched "beep"-noise and then it runs back
; this procedure can be endless.

Now i found out that the Motor driver (6125B) gets quite warm. Accidently i got with my finger on the components
below the motor driver and then the HDD worked normal, no data loss, no transfer drops, not anything. As soon as i remove my finger,
it will make the problems again. Then I´ve taken a multimeter and measured the passage of the two components, which marked red in the picture and found out,
that the right one shows a value of "2.4" at Diode Test and the left one nothing. I cannot clarify if they are diodes or anything else, since they are complete black and have both no values imprinted. The "good one" is somewhere connected on the lower side of the PCB, and the bad one to a capacitor and i -suppose- that he goes to ground, so -proably- the Motor driver tries to obtain from enywhere else ground and gets hot.

Anyone having an idea what they could be?

Best regards
Stefan

Attachments

[stef]

Hm...according to the Datasheet of a L7250 Motor driver it is Pin12 ,called "neg reg comp" - whatever this means. This pin is connected up to an Resistor in parallel with an Capacitor, from there into the "unknown part" and after that part in another capacitor. Pin11 called "n_Feed" is also involved. Let me guess - both are proably fuses? They have a white body like an resistor, but the painting on top is black. I know only (until now) complete white fuses.

[stef]

Well, i removed the faulty part, measure it outside, deifinitive death and it turns to be out that it proably is a very small coil and its function seems to be proably noise compensation. The HDD works when the faulty part is being bridged (i know i should not do that, but i have no spare part here and could not the right part from anywhere), but with a strange access noise. But at least i can get access and copy the data to another HDD.

[BlackST]

Since when Samsung uses L725x ?

[stef]

I stumble across the Datasheet of an L7250 while collecting information about my error and since the pinout makes sense, i guess that it is proably an identical part, as it could be. I guess that the SH6125B is not the only motor driver with the same functionality.

[BlackST]

No they aren't same part. Good luck.

[stef]

Well, i have taken this Information from this Thread - maybe i misunderstood it, although the I/O on the referring pins seem to make sense ( i didn´t check the entire pinout cause i don´t have a found a PDF for the 6125 so far).

samsung-spinpoint-hd103uj-will-not-spin-t13430.html

At least the "bad solution" did work