The SMOOTH CHIP heating up, would the DONOR PCB cure HDD

[Smyans]

My Seagate 7200.11 stopped working and when I diagnosed the problem, I noticed that when I connected the SATA power cable to the HDD the SMOOTH chip began to heat up pretty rapidly.

Would it be possible to cure the Hard Disk using a DONOR PCB and desoldering the EPROM from the patient PCB and putting it in the DONOR PCB?

If there is somebody who has same type of Seagate Harddisk, so I'll insert information concerning the Harddisk here underneath.

If such a Harddisk or DONOR PCB can be found, I would like you to let me know.

Here is the Harddisk information:

Here is the information concerning Seagate Hard Disk that I would like to purchase, in order to be able to swap the PCB and EPROM.

S/N: 9QK1CWD5

Harddisk Type: SEAGATE ST3750330AS

P/N: 9BX156 – 568

Firmware: SD81

Date Code: 09077

09077 corresponds to 2008 August 22nd
Site Code: KRATSG

PRODUCT OF THAILAND


MCU Information:

ST V523C

SEAGATE
DAZZOO1TQ
9E805116
AA116
TWN 99 816

[dmarques]

Hi,

First of all, your drive doesn't spin at all?
That could indicate a problem in the PCB, and depending on that, your solution could be possible.

[poehere]

If the smooth chip is heating up as you say it is one could be your board is bad and two could mean there is internal problems with preamp on this one. Can try frist a donor pcb to see if it helps and if not then you will need some help from a DR company to do this one for you.

[Smyans]

Thank you for your kind reply!

Would it be possible for me to somehow measure with multimeter,whether the Preamp is OK or not?

Do you mean, that I should first acquire the PCB (I received a positive reply from the "PCB Solutions", telling me that : "We have a physically identical board to yours, however, the firmware is different. To ensure compatibility, a firmware transfer is necessary." Then they suggested me, that would do the firmware transfer for a 10 Dollars extra amount. The price of the PCB would be 39,95 Dollars!

Smyans

[fzabkar]

Thank you for your kind reply!

Would it be possible for me to somehow measure with multimeter,whether the Preamp is OK or not?

Do you mean, that I should first acquire the PCB (I received a positive reply from the "PCB Solutions", telling me that : "We have a physically identical board to yours, however, the firmware is different. To ensure compatibility, a firmware transfer is necessary." Then they suggested me, that would do the firmware transfer for a 10 Dollars extra amount. The price of the PCB would be 39,95 Dollars!

Smyans

If your preamp is shorted, then a replacement board may be damaged as well, but at least you will know that the problem is internal to the HDA.

Alternatively, you can power up your board on its own and measure the voltages at the DC-DC converters. This will tell you whether the SMOOTH chip is alive. You will also be able to identify the supply rail for the preamp. A continuity test from the DC-DC converters to the preamp connector will identify the preamp's supply pins, which will then allow you to test for a short circuit.

If you need help identifying the test points, upload a detailed photo of the board, and zoom up on the coils around the SMOOTH chip.

[Smyans]

Here are some photos concerning the PCB of my Seagate ST3750330AS

http://www.flickr.com/photos/smyans/5240679801/

http://www.flickr.com/photos/smyans/5241274526/

http://www.flickr.com/photos/smyans/5241417620/

http://www.flickr.com/photos/smyans/5241417350/

http://www.flickr.com/photos/smyans/5241416942/

http://www.flickr.com/photos/smyans/5240821617/

http://www.flickr.com/photos/smyans/5240821151/



http://www.flickr.com/photos/smyans/5240820907/

[Smyans]

fzabkar

Thank you for your reply!

Here are the photos on SMOOTH chip and the coils around it!

http://www.flickr.com/photos/smyans/5241552423/

http://www.flickr.com/photos/smyans/5242147502/

[rameez]

If you motor is jam pcb would cause the same problem Smooth chip would heat up .

[Smyans]

rameez, how to know if the motor is jam, prior to purchasing a donor PCB?

Is there some method to analyze it?

[fzabkar]

Looking at the board with SATA connectors toward the bottom of the screen ...

The leftmost DC-DC converter supplies the negative voltage (-5V ?) for the preamp. It is comprised of the 4R7 coil and the 8-pin IC above it (E3P1S). The IC probably consists of a MOSFET chopper and a Schottky flywheel diode.

I believe that the MCU requires two Vio supplies, one for the SDRAM, and the other for the remaining IO functions, including the serial flash EEPROM and the serial RS232 terminal interface. Let's refer to them as Vio_1 and Vio_2, respectively.

By way of example, here is a Philips MCU based on an ARM9 core:
http://ics.nxp.com/literature/leaflets/ ... pc3180.pdf

The above MCU requires 1.8V for its SDRAM interface, and 3V for the rest.

On your board, the middle DC-DC converter (4R7 coil + 6-pin IC) provides the Vcore supply (+1.2V ?) for the MCU.

uPA2680T1E, NEC, MOSFET with Schottky Barrier Diode, marking A2680, 6-pin:
http://www.datasheetarchive.com/pdf-dat ... 436380.pdf

The rightmost DC-DC converter (2R2 coil + 6-pin IC) provides the Vio_2 supply (+3.3V ?) for the MCU and flash memory.

The linear 2.5V regulator (ST1L02PM) provides the +2.5V Vio_1 supply for the MCU and SDRAM.

It appears (from a discussion in a different forum) that the hit entered your board via Rx, shorting it to ground. It then damaged both Vio supplies and shorted them to ground. Since the preamp is not powered from either of the damaged rails, I expect that it would be OK. However, any device that is connected to either rail must be suspect. Unfortunately that includes your flash memory. On the plus side, the flash EEPROM is specified for supply voltages up to 3.6V, so it probably survived. It suspect that the damage is confined to the MCU.

The bottom line is that a board swap and EEPROM transfer will probably work, but it will only return you to your starting point, ie the BSY bug. At this point you MUST use a board that has your original EEPROM data. The MCU needs these data to locate the Service Area on the drive, and to load the unique, "adaptive" information.

Needless to say, your interface cable cannot be trusted. I believe the damage was somehow caused by the external 3V supply.

BTW, the partial pinouts for the preamp connector are:

Code:

Pin #   Function
---------------
4      Ground
6      -5V for preamp
8      +5V for preamp
10      Ground

5       Voice coil (current sensing end, 4 x 1R00 resistor array)
7       Voice coil

[Smyans]

I just would like to thank you fzabkar for all of your efforts to provide solution to my problem.

Here it is in a nutshell, the outcome of my unbricking of the Seagate ST3750330AS.

I got it working and here are the main issues concerning how I did it!

1. I purchased a donor PCB based on your advice fzabkar, from PCB Solutions. They were very helpful!

2. I let the TV/AV repair shop to transplant the EPROM Chip from the faulty PCB to the donor PCB.

3. I used the battery pack, containing two AAA batteries and the total voltage output was appr. 3 volts. I connected the + of the Battery Pack to the RED Wire of Nokia CA-42 and the - of the Battery Pack to the BLACK Wire of Nokia CA-42. And then I connected the TX and RX wires to the PCB pins.

4. I run some Loopback tests prior to starting the unbricking of Seagate ST3750330AS and I also used 3 different Terminal Programs to make sure that the Loopback was working properly. Those Terminal Programs were: 1. 232Analyzer 2. RealTerm 3. Hyper Terminal and the operating system that I used during the unbricking process was WINDOWS XP HOME EDITION!

5. After some initial hiccups, I was finally able to get the whole process done and I got the Seagate ST3750330AS recognized again by the BIOS!

Thank you very much fzabkar and if there were some others who were also helping me to get the ST3750330AS working again, so I would like to thank you too!

I just would like also to reiterate how great and wonderful it is, that there are forums where it is possible to get high tech and very sophisticated help to ones HDD related problems.

Smyans