Hello,

I recently thought of repairing some of my old drives. The ones that are behaving very interesting are 2 Samsung hdd's Spin point model SV2042H and another one SV0761H. They are both doing the same thing, not powering up the motors, checked with a voltmeter. Before i start diagnosing this i wanted to ask here if anyone ever encountered this problem and if i can receive at least a hint of the area i have to search. I will start by tracing the backwards the power circuits for the motors and see what parts are on this circuit. It really seems like some kind of protection, but how they ended up like this, well, i can't remember...

Anyway if someone can give me some hints on this it would be appreciated.

One last thing...i noticed that the jumpers used for setting the master slave, etc have 3 positions labeled from the ide connector to the power connector as follows Master, Slave , Cable Select and the fourth it's not labeled...what this stands for?

Thank you very much for your kindness and looking forward for some info or small hints.

Alex.

Please don't take this a me being rude or anything, but if you don't even know basic IDE jumper settings you are in way over your head trying to repair hard drives.

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Data Medics - Hard Drive, SSD, and RAID Data Recovery Service Company

I think the OP understands the basic jumper settings. It's just the last jumper that he doesn't understand. However the following article should enlighten him:

How to connect a terminal cable on a Samsung drive ?
http://www.hddoracle.com/viewtopic.php?f=116&t=189

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A backup a day keeps DR away.

If you upload detailed photos of each PCB, I will try to help you locate the basic test points.

You may find the following article helpful:

Tutorial - Linear and Switchmode Regulators used in HDDs:
http://www.hddoracle.com/viewtopic.php?f=59&t=231

_________________
A backup a day keeps DR away.

Hello folks,

Thank you very much for your reply.

First of all @data-medics, i do not consider you rude, but you are over underestimating someone that you do not know and your answer it's off-topic, but i do not mind as everybody it's free to answer whatever they want, i do not feel offended in any way.

@fzabkar, thank you very much for your reply. I was suspecting that pin having to do something with the HDD communication to a terminal, but i just couldn't find that info, however i didn't searched too much as these drives are just sitting for some years and i decided to have them fixed as the problem , indeed, seems to be power related or something...like a bad voltage regulator which when on load cease to function...anyway ! I will study the documents and see if they enlighten me !

Attached are the photos of the PCB'S and the filename of each photo represents the HDD model. For one model i put two chip side pics as i do not like how one of them looks, but hope they are good enough. You can magnify the pics and they look very good actually.

Thank you very much for your kindness.

Alex.

@fzabkar: i must say that after reading those two articles, they surely enlighten me. Thank you very much for your kindness and information.
After reading the post about the terminal connection for the Samsung drives a possible scenario came up to me, regarding these two Samsung drives. It goes like this : On the sticker they have a schematic of how to set up the drive to be SL, MS or CS...The schematic it's very ambiguous as you can not tell how it's lined up with the power connection and the IDE connector so one could accidentally short pins TX/RX when setting Master.

In the case ( very probable ) that this was done and maybe that's why it doesn't start, shorting the Tx/Rx pins could damage a part , or maybe the drive entered a protection mode of some kind...whatever the outcome of shorting those pins would be i think this the right place to start,,,pins shorted on Tx/Rx

Below you have a photo of the sticker on the HDD with the set up pins. As you can see you can not tell if you should short pins from the left or pins from the right to set Master. Also the print on the PCB plastic, adjacent to the pins it's very hard to see

Here is a tutorial that I wrote when I was working with an older Samsung PCB.

Tutorial - how to locate the basic test points of an unfamiliar HDD PCB:
http://www.users.on.net/~fzabkar/HDD/Tu ... 0411N.html

Your BF41-00041A PCBs are a few years older, but the tutorial should still be helpful.

I usually begin by identifying the major ICs and their power requirements. The 88C4200 Read Channel and A43L8316V SDRAM require 3.3V, so I would be looking for a 3.3V regulator. This appears to be the RT9164.

The "8G0S" device (QF1) is probably an 8V linear regulator. It appears to supply the preamp via an 1R0J inductor (LF1).

I haven't determined the function of transistors (?) QW1 and QW2, but it appears that all "xWn" components are associated with the read channel. Similarly, all "xFn" components appear to be associated with the HDA connector/preamp.

I would measure the test points identified in the attachments.


RT9164-33CG, RichTek, 3.3V, 1A Low Dropout Positive Voltage Regulator:
http://www.cheertech.com.tw/RichTek%20C ... 164-19.pdf

88C4200, Marvell, Disk Drive Read Channel, 3.3V:
http://pdf.datasheetarchive.com/datashe ... 647516.pdf
http://pdf.datasheetarchive.com/datashe ... 123801.pdf

A43L8316V-10, AMIC Technology, 4Mbit, 128K x 16 Bit x 2 Banks Synchronous DRAM, 3.3V:
http://pdf.datasheetcatalog.com/datashe ... 9223_1.pdf

AT49F1024-45VC, ATMEL Corporation, 1-Megabit 64K x 16, 5-volt Only Flash Memory:
http://www.gaw.ru/pdf/Atmel/at49/AT49F1024-1025.pdf

L78L08, STMicroelectronics, 8V, 100mA, positive voltage regulator, SOT-89, marking 8G:
http://www.st.com/web/en/resource/techn ... 000446.pdf

_________________
A backup a day keeps DR away.

Thank you very much for all information, i will start diagnosing and checking and see what comes up. I already tested that voltage regulator, RT9164, and it works. I have an input of 5V, good ground and a stable output of 3.34V....

One more thing i omitted to tell you here about these two drives...they have a clicking sound, very faint and diagnosing with a stethoscope i found out that the noise it's not from the motor, but from the heads arm area...

Very strange...will keep updated as soon as finish tests on the PCB.

As for the repairs, until now, because i am doing motherboard repairs and stuff like this, i repaired HDD's only at software level, or how can i say, i used only software that regenerates hdd's corrects magnetic errors, recovers data, formatting and aligning partitions and so on. Occasionally i had HDD's that had some electronic parts failed and serviced them, but my work on hdd's i admit it's quite limited, i never went into the darkness of the hdd world But i am willing to learn and to extend my knowledge to a certain level in the hdd field.

It sounds like your drives have a seized spindle bearing or a stiction fault (heads stuck to platters). The PCBs are probably OK, but you could check around the motor controller (HA13626), and measure the resistances of the motor windings.

You could also measure the spindle motor current, probably at the 1R00 resistors.

Measuring VCM and Spindle Motor Current:
http://www.hddoracle.com/viewtopic.php?f=59&t=204&p=484

_________________
A backup a day keeps DR away.

After doing some measurements here's what i compe with :

1. According to the schematic for the IC 13614FH ( i guess it's close enough , i couldn't find the exact datasheet ) we have the following :

Pins: 20,21,27 control the 3 phases, they go directly to the motor. With the motor disconnected i get a good reading to ground, about 0.5 ohm , 99% pure ground. This is the spindle controller. On the sensing resistors, of course i get nothing with the hdd plugged in the power source. The spindle driver it's feed by a mosfet. The mosfet gets power in the drain at pin 31, the gate it's controlled by the brake control inside the IC and the source exists on pin 31 and goes to pin 28 were it feeds the spindle driver. I checked the drain to ground, no problems and the source to ground and again no problems.

After letting the hdd to sit for about 30 minutes ( without power ) the short on the phases pins disappears, but as soon as i connect power to the drive the condition occurs again.

The only problem seems to be the output for the phases, they are ground, which might explain the cycle, short.

2. The VCM current sense resistors are getting pulses from 20 mV to 55-60 mV according to the noise, the frequency it's the same, which i think it's normal as long as i have that short on the spindle driver.

The motor measures 2.7-3.0 ohm from COM to phases and 5.0-5.4 ohm between phases. I do not see any problem here.

Judging by all this i think that the IC it's bad, what do you think?

If you need more info, just let me know,.

Thank you for your support.

@fzabkar, well what do you think about the data i've got from the HDD, how does it sounds to you? Any feedback would be appreciated.

Thank you.

The uppermost MOSFET is turning on, so it's OK. ISTM that the low-side MOSFETs for each of the motor phases are OK also. The reason that they test shorted and then recover could be due to residual capacitance which is turning them on until the capacitance decays.

I don't know why you are measuring activity at the VCM current sense resistor, but that could be just my lack of understanding. I would measure the voltage across the motor current sense resistors (ISENSE). That should tell you whether there is any current flowing through the motor. I would have expected that you would see voltage pulses at each of the motor phases.

_________________
A backup a day keeps DR away.

No current flowing thru the motor. Just those pulses at the VCM, which after a period disappears completely, something it's shutting down... and then after a time it begins again the same cycle of on and off at a very low voltage...but indeed nothing on the motor spindle.

I will investigate further and come with results, if any

Thank you for your support.

Alex.

Hello.
I desperately need "Tutorial - how to locate the basic test points of an unfamiliar HDD PCB".It seems that below link have been broken.
http://www.users.on.net/~fzabkar/HDD/Tu ... 0411N.html
Is there anyone who still have this tutorial?

Use https://web.archive.org/web/20230522151241/http://www.users.on.net/~fzabkar/HDD/Tutorial_SP0411N.html

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Data Recovery Services in the UK.
https://www.usbrecovery.co.uk/

Thank you very very much for your link!!
I really want to fix broken SV1021H hdd drive.
I measured voltage of 8G0S device(QF1) pin1 was 7.9VDC and pin3 was 12.5VDC.
Voltage of RT9164 IC was 3.3VDC and 5VDC.
But Spindle Motor won't rotated at all.
So I need more information in order to locate culprit.

I haven't been able to find a good photo, but there are two "BC" components (QW2 and QW1) that look like they may be power related. Can you tell us the voltages at these components (and upload a detailed photo)?

_________________
A backup a day keeps DR away.

Thank you very much for reply!
As I have no information about these transistors(QW1 and QW2) So I measured its voltage in the same way as 8G0S device(QF1).
I placed black probe on largest pin on the top and placed red probe on pin1 and pin3.
It was measured 0.025-0.028VDC between pin1 and largest pin and measured 0.645-0.648VDC between pin3 and largest pin.
and I took pictures Top and bottom of PCB.(SV1021H)
I have spare SV1021H,So I tried PCB swap but Spindle Motor still won't rotated at all.
https://i.ibb.co/xfkWF8j/IMG-20241019-135827.jpg
https://i.ibb.co/ysS5XRk/IMG-20241019-135831.jpg
https://i.ibb.co/BGzrQ50/IMG-20241019-135855.jpg
https://i.ibb.co/LrpQ43n/IMG-20241019-135859.jpg
https://i.ibb.co/Zhgmj7F/IMG-20241019-135906.jpg
https://i.ibb.co/w0Ztp7T/IMG-20241019-135910.jpg
https://i.ibb.co/nsqnNTD/IMG-20241019-135917.jpg
https://i.ibb.co/hL6KYwm/IMG-20241019-135924.jpg
https://i.ibb.co/ch1Nz5H/IMG-20241019-135935.jpg
https://i.ibb.co/bztp7CG/IMG-20241019-135941.jpg
https://i.ibb.co/cLqYD31/IMG-20241019-135947.jpg
https://i.ibb.co/hVknFrL/IMG-20241019-140012.jpg

I'm sorry that it seems that all of picture, which I have uploaded, was very blurry.
So I took pictures with high resolution smart phone.

https://i.ibb.co/xDrcbsW/20241019-172721.jpg
https://i.ibb.co/QN63smf/20241019-172559.jpg

There is a hole in the motor controller IC (HA13...).

The 22uF 25V capacitor has also been disturbed (?).

I would measure the resistances between the motor terminals.

_________________
A backup a day keeps DR away.