Fried PCB on newest seagate drive where is the eeprom chip?

[quantum3]

I set the HD on the bottom of the metal case while running and smelled smoke. Yep, it was a very dumb move. the pcb board is 100664987 REV B and so far donerdrives do not have the REV B in stock. I did get a replacement from seagate and it has the same board. I was thinking of using a heat gun to pull the old chip of of the old board and put on new board. Pull the data off of the old board then switch back and send it in. Would this work? Is this a good idea? and which of the 2 8 pins chips needs to be moved please?

Thanks,
Q

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[quantum3]

more pics. If you look at pic 4 you can see the 1st two of the 4 zeros in a row are discolored. I think this is where the damage took place. Now my HD doesn't spin at all.

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[fzabkar]

more pics. If you look at pic 4 you can see the 1st two of the 4 zeros in a row are discolored. I think this is where the damage took place. Now my HD doesn't spin at all.

It appears that the 5V TVS diode may be shorted, in which case those two zero-ohm resistors would probably be open circuit. If that was all that was wrong, then the solution would cost you nothing.

See http://www.users.on.net/~fzabkar/HDD/TVS_diode_FAQ.html

However, since you cannot determine what other damage may have been done, it might be safest in this case to transfer the flash memory. I'm fairly certain it's the 540-7561x chip, but let me identify all the others just to make sure. I'll follow up this post as soon as I can, unless someone else beats me to it.

[pcimage]

Fzabkar is right, best solution would be to get a new PCB and transfer the 540-7561xx chip.

You could of course just remove the suspect diode, but safer to go the new PCB route IMHO.

[quantum3]

Thanks for the replys guys. I cant find a pcb replacement because the board is so new. There are plenty of rev a out but no rev b as of now. I just need to get the data off then I dont care about the hd. Could you please tell me where on the board the diode is I need to remove and what is the worst case scenario if I remove the diode and plug it back into the system. Will the pc be in danger or just the hd? Thanks!

[BlackST]

Why not get a whole drive instead of searching for the PCB ?

(I have many of them , but I don't sell (yet) parts neither single drives to end-users)

[sathyan]

Could you please tell me where on the board the diode is I need to remove and what is the worst case scenario if I remove the diode and plug it back into the system. Will the pc be in danger or just the hd? Thanks!

TVS are for protection of the pcb of the hard disk, the disk will work without these diodes, but you have to be sure of your pc power supply(SMPS),else it can damage the pcb of the drive.
It shoudn't put your pc in danger.

The pictures are not very clear to identify properly the diodes, but if you have a multimeter you can check if your TVS is ok or not.

Also check the 0 ohm resistors that have some sort of visible burn marks, and replace them (or use wire warp )

To check TVS is ok or not:
After you replace the faulty 0 ohm resistors, check if these are shorted to the ground(Chasis or screw area).They should not be shorted to ground. if so then TVS blown and have to be removed. There are two in pic4(right hand bottom) and one below smooth pic3.
check for shorts in them .
Search for TVS will give you a lot of info about them and how to check them,
Also there are chances that something else might have failed,
DIY has its risks,
good luck

[fzabkar]

Thanks for the replys guys. I cant find a pcb replacement because the board is so new. There are plenty of rev a out but no rev b as of now. I just need to get the data off then I dont care about the hd. Could you please tell me where on the board the diode is I need to remove and what is the worst case scenario if I remove the diode and plug it back into the system. Will the pc be in danger or just the hd? Thanks!

It is not clear what damage your board has sustained. You say that you placed the HDD at the bottom of your PC case, so this originally implied that you had shorted the PCB against the metalwork. I doubt that this is really possible. Have you examined whether the metalwork is flat, and whether you can see daylight if you run the edge of a ruler along your HDD's casting?

If you can positively eliminate such an event as a reason for the failure of your HDD, then the only real conclusion we can make, if the 5V TVS is shorted, is that the power supply overvolted your drive. If this is the case, then you would need to replace the PSU, otherwise it will probably damage your HDD after you remove the shorted diode.

To add to what sathyan has suggested, you could flow a blob of solder over each of the two resistors. IMO the 5V TVS diode is probably the second diode from the right in the bottom right corner of 4.jpg. It would help us if you could identify the markings on each.

As for the diode below the SMOOTH chip, I suspect it is probably a Schottky rectifier, not a TVS diode. Once again a marking code would help us identify it.

The 8-pin chip at 10 o'clock to the SMOOTH IC in 1.jpg is actually a FETKY. It consists of a MOSFET and Schottky rectifier, and together with the 1R2 coil it forms the -5V supply for the preamp. It is not a flash memory. When looking for donor PCBs do not make the same mistake as the person in this thread:

st2000dm001-pcb-motor-chip-issue-t24263.html

References:

NTMD4184PFR2G, On Semiconductor, marking 4184P, P-Channel, FETKY, S08, -30V -3.8A:
http://www.onsemi.com/pub/Collateral/NTMD4184PF-D.PDF
http://www.bdtic.net/DataSheet/ON/NTMD4184PF.PDF

K4T51163QJ-BCE7, Samsung, DDR2 SDRAM, 512Mbit, 32M x 16, 1.8V:
http://www.samsung.com/global/business/ ... _rev11.pdf

[quantum3]

Thanks so much for taking the time to help with this! Here are a few more pics that show the chips close up so you can read them. As for how it happened I THINK I know what happened. I was using a (Y) normal 4 pin power connecter to a 2 sata power connecters. It not only fried this board but also a 250 gb drive as well. the other 4 drives in the pc are all fine. I pulled the splitter and trashed it and I hope that is the end of it. If I am able to get this board working I will place in the spot of one of the other drives just long enough to copy the data then I will pull it back out. Please look at these pics and let me know what you thine and thanks again!!!!
Q

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[quantum3]

On a side note since no one carries a 100664987 rev b board what are my chances using a 100664987 rev a board and just moving the eeprom over?

[fzabkar]

Thanks. Those photos are much clearer.

The 5V TVS diode is the one with an "AE" marking and Littelfuse logo. The "12T" component to its right is the 12V TVS diode.

The "33C" diode below the SMOOTH chip is indeed a Schottky diode. It is associated with the 1R0 (1uH) inductor to its right. Together they form part of a switchmode supply. Do not remove it.

The part number of the flash memory appears to be EN25S40. The marking code is actually "S40-75GIP".

EN25S40, Eon Silicon Solution, marking cFeon S40-75GIP, 4 Megabit 1.8V Serial Flash Memory with 4Kbyte Uniform Sector:
http://www.essi.com.tw/upfile/p20122717317.pdf

[fzabkar]

One more datasheet ...

LX7157B, Microsemi, step-down PWM regulator IC with integrated high side P-Ch MOSFET and low side N-CH MOSFET, 2.2MHz, 3V to 5.5V:
http://www.microsemi.com/document-porta ... -lx7157bds

Looks like the above IC might be vulnerable to an overvoltage on the 5V supply. Its absolute maximum rating is 7V. The 5V TVS diode should clamp voltages just below that maximum, but it could be close.

[quantum3]

Thanks for the info.
So my best bet to try to get the data off now without waiting for a new REV B board is to flow a blob a solder over the 2 diodes next to each other on the far right of the board and cross my fingers correct?

Thanks again!
Q

[Vulcan]

So my best bet to try to get the data off now without waiting for a new REV B board is to flow a blob a solder over the 2 diodes next to each other on the far right of the board

NO! Depending on your PSU & cabling etc., the worst case after doing that could include a big bang and/or fire and/or personal injury etc. You might be lucky and have none of that happen, but it certainly won't fix your board to follow your plan.

I disagree with some of this thread so far, so I'm not going to get involved now - I'm just trying to avoid you causing a bigger problem due to your misunderstanding of the advice given previously by others. You'll need to wait for them to explain your mistake & suggest next actions.

[sathyan]

Thanks for the info.
So my best bet to try to get the data off now without waiting for a new REV B board is to flow a blob a solder over the 2 diodes next to each other on the far right of the board and cross my fingers correct?

Thanks again!
Q

you got the wrong idea, please read carefully what has been posted.
The blob of solder or wire warp on the two (Visibly) burnt 0 ohm resistors just below the power connector, NOT OVER TVS DIODES.

As suggested, use a new good power supply to power up the drive.

Try powering on only the pcb (without connecting it to the drive) and check if the power supply powers on.

IF YOU ARE CONFUSED OR NOT SURE , stop ,DIY easily degrades the drive and spoils the chances of recovery later by others.
IF data is important , dont take the risks,

[quantum3]

Thanks for the clarification. I will just order a rev a board and move the eeprom over and see what happens.

Thanks again!

[fzabkar]

So my best bet to try to get the data off now without waiting for a new REV B board is to flow a blob a solder over the 2 diodes next to each other on the far right of the board ...

I wrote "flow a blob of solder over each of the two resistors". These are marked with zeros. You also need to remove the 5V TVS diode ("AE" marking) with flush cutters.

However, before you do anything, spend US$5 on a digital multimeter and make some measurements. Then report back.

If you can't follow the above advice, then how do you expect to do something that is potentially more dangerous, ie desoldering and resoldering an 8-pin surface mounted IC?

If I were you, I would contact onepcbsolution.com. They offer a firmware transfer for US$20 if you supply the PCB, and $0 if you buy the PCB from them.

http://onepcbsolution.com/phone-orders.html

Best of luck.

[quantum3]

Thanks for your advice. I have sent my board to donordrives because its the closest to my location. They said they will have the REV B boards sometime this week and they will move the chip for me.

Thanks again

Q