ST3250410AS burned pcb

[ephraim2]

hello friends

we received yesterday ST3250410AS with burned pcb.

P/N 9BX154-303, F/W 3.AAC, DATE 08296, Thailand.

we attached couple of photos which describe everything.

is anything can be done?

tks and brgds
ephraim

Attachments

[northwind]

Did you try swapping pcb+rom?

[ephraim2]

not yet

i wait to get more advises

tks a lot

[Nick_CT]

You don't need more advice at this point. Follow northwind's advice and try and new PCB with the ROM moved across. Hopefully the preamp will be ok.

[BlackST]

With all this mess, ROM is the latest problem... if it has ever been...

[AzureSky]

I think the motor might be shorted or burned ?

[fzabkar]

I think the motor might be shorted or burned ?

Could be. It looks as if the motor controller's damage is in the area of VCM and spindle motor pins, so I would suspect that the drive may have sustained an overvoltage on the +12V supply. If the 12V TVS diode tests shorted, then this would confirm it. Moreover, as there does not appear to be any visible damage on the +5V side of motor controller, then there is a good chance that the digital components have survived. That includes the "ROM". ;-)

[ephraim2]

tks you all fzabkar AzureSky BlackST Nick_CT northwind for your help.

i believe 1st thing to do is to find a donator drive

does anybody know where to find?

a good drawing of the pcb is very needed as well

tks u all
ephraim

[AzureSky]

Ebay can be a good source of spare hdd's.

I think a simple ohm-check of the motor might be in place before you try swapping the PCB's around to prevent damage to new PCB if something is still wrong.

[ephraim2]

tks a lot AzureSky

we'll do that

brgds
ephraim

[ephraim2]

hello northwind

although we have some experience we'll be happy for assistance.

for the moment we need 1. the layout of the pcb
2. find a donator hdd. ebay is always a good source. at the moment we are looking in our neiborhood.

tks and brgds
ephraim

[BlackST]

@ephraim, BEFORE searching for PCB, DO CHECK EVERYTHING ELSE.

[AzureSky]

I think the motor might be shorted or burned ?

Could be. It looks as if the motor controller's damage is in the area of VCM and spindle motor pins, so I would suspect that the drive may have sustained an overvoltage on the +12V supply. If the 12V TVS diode tests shorted, then this would confirm it. Moreover, as there does not appear to be any visible damage on the +5V side of motor controller, then there is a good chance that the digital components have survived. That includes the "ROM".

Yep. I would agree it might be and overvoltage event. Second thought is failure on shutdown and then burn on next startup - since VCM is powered by the spindle motor for the time of a rapid power loss. Or the motor maybe seized and burned out the chip - but the controller does have its overcurrent protection circuitry.
I really wonder if VCM and Motor are ok. Something went wrong really bad here. I would check the PSU of that PC as well - might give out a few clues about the failure.

[BlackST]

Instead of speculating and guessing, do one thing : check if the headstack is STILL working. If the HS is killed, at this point a problem at motor level is the least problem.
AND in any case the complete loss of the PCB , even with ROM would not be a problem, if you know how these puppies work. It will require a lot of additional work and ajustments but you'll succeed.

[fzabkar]

hello northwind

although we have some experience we'll be happy for assistance.

for the moment we need 1. the layout of the pcb

All you need to do is to locate the serial flash memory IC, if it exists (in a corner of the PCB, at the SATA end), confirm that it isn't shorted, and then transfer it to a replacement PCB.

However, before doing the above, I would perform an ohms test on your spindle motor windings and VCM, and test each of the onboard power supplies for short circuits, including the preamp supply. This will tell you whether there are any obvious HDA problems.

If you upload a detailed photo of the entire PCB, then I will be able to tell you where to measure.

The following datasheets should help you:
http://www.users.on.net/~fzabkar/HDD/HD ... Flash.html
http://www.users.on.net/~fzabkar/HDD/HD ... _Regs.html

[ephraim2]

tks fzabkar

i am attaching some more pictures of pcb

tks and brgds
ephraim

Attachments

[fzabkar]

I have identified the components as best I can from the photos you have provided. There may be errors.

The serial flash memory will probably have a "25" in its part number. It is instantly recognisable because it is located on its own. The other two 8-pin ICs are adjacent to coils. This identifies them as PWM controllers or FETKYs (MOSFET + Schottky diode). Coils are the landmarks that identify switchmode DC-DC converters.

I suggest that you first test the TVS diodes. I expect that the 12V diode may be bad.

I would then test the resistances of the spindle motor windings. I expect that you should measure something of the order of 1 - 2 ohms between each pair of terminals (1&2, 2&3, 1&3).

Next you need to identify the VCM and power pins at the preamp contacts on the PCB. The +5V and Ground pins can easily be determined by testing for continuity with the SATA power connector. I'm guessing at the -5V pin, but it will probably be grouped together with the +5V and ground pins. It will also connect to the anode of the Schottky diode in the FETKY package in the -5V DC-DC converter. You can refer to my database for the datasheet of the device.

The VCM pins would be identifiable as two heavy traces leading towards the motor controller IC. One will be connected to the VCM current sense resistors. I have identified what I believe to be two sets of current sense resistors. One will be for the VCM, the other for the spindle motor. The spindle motor current sense resistors will be connected to ground, whereas the VCM resistors will be floating (IC damage notwithstanding).

Once you have identifed the preamp supply pins and VCM pins, then you can measure the resistances at the corresponding pins of the HDA connector.

Attachments

[ephraim2]

tks a lot fzabkar

we'll follow your instructions.

we'll let u know results

tks again
ephraim