ST380011A ROM

[Dizidago357]

Hi,

I have a ST380011A that doesn't spin. With a donor board on it, it spins up fine (doesn't ID though). I was wanting to try a ROM swap, but don't see a standard one (starting with "25P") and was curious if it was embedded or not. Please see the picture below and if anyone has any advice, thanks in advance.

Dizi

Attachments

[Samo]

Rom is masked into the MCU, better to connect serial port and see the terminal output.

[harddrivedonor]

you need to match the main controller chip too. `AGREE` in your case

we have it in stock.

[Dizidago357]

Samo,

Terminal output is

Interface task reset
1024k x 16 buffer detected
ALPINE - 1_Disk M-21 11-25-03 18:53

Buzz -
Buzz -
Buzz -
Buzz -
Buzz -
Buzz -
Buzz -
Buzz -
Buzz -
Buzz -
Buzz -
Buzz -
Buzz -
Buzz -

And just continues buzzing, left it like that for a few minutes and the drive still stays busy. Is the "buzz" the board querying the drive to start up? Or is it something else? Do you know of anywhere with FAQs or a good guide to check out regarding terminal commands and appropriate (or error code) outputs?

Dizi

[Samo]

It's not spinning, you should check the reason, is it bad PCB or other mechanical reason.

[fzabkar]

FYI, that component is a FETKY.

NTMSD3P102R2, ON Semiconductor, marking E3P102, FETKY P–Channel Enhancement–Mode Power MOSFET & Schottky Diode, Dual SO–8, –3A, –20V, 0.085 ohms:
http://www.onsemi.com/pub/Collateral/NTMSD3P102R2-D.PDF
http://www.datasheetcatalog.org/datashe ... 02R2-D.PDF

See my HDD IC database:
http://www.users.on.net/~fzabkar/HDD/HDD_ICs.txt

BTW, I believe the buzzing is referred to as "Spin Buzz". AIUI, the SMOOTH chip is trying to kickstart the motor.

[Dizidago357]

fzabkar,

Thanks for the info. Any suggestions on potential TVS locations?

Also, looked through your IC sheet, but could not locate the MCU chip on this drive

Thanks,

Dizi

[fzabkar]

There is no reason to consider the TVS diodes. If either were shorted, then the board would not power up. FYI, the 5V TVS diode is marked "QE" and is located above the locating hole at the bottom left corner of your second photo. The larger 12V TVS diode is marked "BUX" (?) and is to the left of the same hole.

See my notes:
http://www.users.on.net/~fzabkar/HDD/TVS_diodes.txt

The MCU is always (?) the largest chip. In this case it is the one manufactured by Agere.

The repeating spin buzz would suggest stiction or a seized spindle. It could also be due to a bad motor (open or shorted winding), or bad MOSFET drivers in the SMOOTH chip's output stage. A board swap would eliminate the latter. You should measure the resistances of each of the motor windings. I would expect something in the order of 3 ohms.

[Dizidago357]

fzabkar,

The board is not powering up... Or are you meaning if the TVS diodes were blown then it would not report anything in terminal mode?

When I said I couldn't locate the MCU, I meant on your spec sheet. I saw you had many listed for internal and external ROMs, but could not locate the code from the current MCU in the spec sheet.

As for resistance measuring, which are the motor windings? Are you speaking in regards to copper springs that stick up near the connection to the motor? And also, what's the appropriate range to measure with?

Thanks,

Dizi

[Samo]

Dizidago357
Here is nothing to do with TVS, fzabkar already did dummies explanation
If I understand you right you have swapped PCB with other known good and drive spin fine but won't ID
Just find appropriate PCB and you will have your drive working again!

[fzabkar]

The board is not powering up... Or are you meaning if the TVS diodes were blown then it would not report anything in terminal mode?

That's right. The fact that you'r getting a terminal report means that the MCU is alive. This means that its Vio and Vcore voltages are OK. Furthermore, since these voltages are generated and monitored by the motor controller IC, this would mean that the SMOOTH chip also has sanity. If the voltages weren't up to spec, then the SMOOTH chip would not have released the Power-On-Reset signal to the MCU. So, yes, the board has powered up, even though it has not been able to spin up the motor.

A TVS diode is connected between its associated supply and ground. It goes short circuit after it is subjected to a sustained overvoltage. When the external PSU sees this overload, its own internal protection circuitry shuts it down. The fact that the external supply has not gone into protection mode means that neither TVS diode is shorted.

When I said I couldn't locate the MCU, I meant on your spec sheet. I saw you had many listed for internal and external ROMs, but could not locate the code from the current MCU in the spec sheet.

The MCUs and most of the motor controllers appear to be custom designed for a particular model series. The datasheets are not publicly available. Perhaps some are available after signing a NDA (Non Disclosure Agreement), but I doubt it. I suspect that the SMOOTH ICs are all similar to the L7250, which is publicly documented, but the pinouts are different, and there may be slight differences in function. Most modern MCUs, eg those made by Marvell, appear to use an ARM9 core, with customised I/O modules, embedded boot ROM or flash, read channel, SATA PHY, etc. The pinouts also differ, as do their Vcore and Vio voltages. That should explain why my notes are so deficient in respect of these two chips.

As for resistance measuring, which are the motor windings? Are you speaking in regards to copper springs that stick up near the connection to the motor? And also, what's the appropriate range to measure with?

You could measure the voltages at the motor contacts on the PCB immediately after power on. If one or more of the motor phases shows no voltage "activity", then one would expect a failure in the MOSFET drivers for that phase. These MOSFETs are internal to the SMOOTH chip. Usually when these fail, the damage is visible.

You also need to confirm that the motor itself does not have an open winding. Set your meter on the 200 ohms range and measure the resistances between each pair of terminals on the motor itself, not on the PCB. I suspect that you will see readings of 3 ohms for each of the three phases, when measuring between phase and common, and 6 ohms between two phases.

[BlackST]

Dizidago357
Here is nothing to do with TVS, fzabkar already did dummies explanation
If I understand you right you have swapped PCB with other known good and drive spin fine but won't ID
Just find appropriate PCB and you will have your drive working again!

IF and only IF the PCB is the only problem or something wonderful happened...

Oh, there's always the "B plan" : repair the PCB. Come on, it's easy !

[Dizidago357]

@fzabkar,

The motor windings (A,B,C in first attached) all come back with 3 ohms across one another (A-B, B-C, A-C). However, I'm not sure what you wanted me to measure when you were suggesting 6 ohms readouts... Are the parts labeled A, B, and C the phases, or are they the commons? Can you please label which parts I am supposed to measure?

Also, on the motor contacts you mentioned, I assume you mean the contacts labeled 1, 2, and 3 in the second attachment? If so, just to clarify, I apply power to the drive then measure the voltage from the ground on the power pinout to the motor contacts individually? Just making sure, as not only am I concerned about blowing any components on the board, but also the ground pinouts are on the component side of the board, and the motor contacts are on the reverse side of the board, and throw in powering on a drive right at that split second makes for a procedure with lots of room for errors (i.e. requiring a few practice tries on parts boards). And measure A/C voltage, or D/C?

Thanks,

Dizi

Attachments

[Dizidago357]

Does anyone else have any suggestions? Fzabkar has not been on this forum for a little bit.

Thanks in advance,

Dizi

[fzabkar]

Your motor measurements are fine. The important thing is that the three readings are identical, and are within the ballpark.

The older motors had three phases (A,B,C) plus a common terminal. Yours does away with the common. My estimate of resistances was based on a motor than was at hand. Its phase-to-phase resistance was about 5.2 ohms. This means that its resistance, per phase, is about 2.6 ohms.

As for your question regarding voltage measurements, I would first try measuring the 1,2,3 terminals with the board disconnected from the drive. Afterwards you could take the same measurements with the board on the drive, but you will need to use other, accessible test points.

I have procured a similar PCB and will upload the motor test points as soon as I can confirm their locations.

Edit: Not yet confirmed, but I believe the following is correct:
http://www.users.on.net/~fzabkar/HDD/ST ... or_TPs.JPG