Litte Puff of smoke

Mir96TA

Golden Member
Oct 21, 2002
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Hi there my Backup HDD has created little puff of smoke, then computer got turn off!
Now with this HDD attach computer wont turn on ( I have all sort of Safety feature on P/S)
If I become creative and swap the PCB (if it is avaible)
Can reterive the Data ?
Pic of HDD Sticker is as follow
backupDrive.jpg
 

RebateMonger

Elite Member
Dec 24, 2005
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About the only thing that could create a quick puff of smoke would be the PCB. The internal motor could burn up, but I suspect it the smoke wouldn't easily escape.

I'm going to assume that the drive really is in bad shape and it can't be successfully attached to another PC. Given that, then a PCB exchange is likely the best hope. Given that it's a refurbished drive, that could complicate things.

http://myharddrivedied.com/presentations/HDSerials.html

Your biggest chance of success would be to employ somebody who does this sort of thing for a living. If the data isn't worth that to you, then you should do some research on what to look for when swapping Seagate PCBs. You can find used disks on eBay and I even believe there's a web site that specializes in postings on drives for sale for parts like this.
 

Mir96TA

Golden Member
Oct 21, 2002
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Data is not more then $10 bucks
HDD is in great shape
My nose telling me PCB went POOF
But I can't what excatly wrong!
 

RebateMonger

Elite Member
Dec 24, 2005
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HDD is in great shape.
Not anymore. (grin)

A brand new one is $45 or $60 for a new Seagate 750 GB drive. Unless you need the data, I think the risk is to high to justify spending time and money on a circuit board.
 

Mir96TA

Golden Member
Oct 21, 2002
1,950
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Not anymore. (grin)

A brand new one is $45 or $60 for a new Seagate 750 GB drive. Unless you need the data, I think the risk is to high to justify spending time and money on a circuit board.

heeee ee
Don't need new Drive I have over 4 TB HDD
This was just a Back
I just backed it up
Re build my Raid
Now wanted to restore data and Pooof!
 

RebateMonger

Elite Member
Dec 24, 2005
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Bummer.

That's why, before rebuilding an array, I'd normally want two sets of backups. But I'm paranoid.
 
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Mir96TA

Golden Member
Oct 21, 2002
1,950
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Say any would know what sort of bit I would need to take these screw off the PCB ?
BackoftheHDD.jpg
 

Russwinters

Senior member
Jul 31, 2009
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Swapping PCB won't work.


There are adaptives stored in ROM chip on PCB, this chip is a little more tricky to transfer then just fixing the problem all together.


Grab a digital multi meter and test the two black diodes near the power connector.

Use the diode checker setting (the <| looking one)

the bigger on is the 12v, smaller is the 5v.

First touch the probes together once in diode mode, and note what the readout is.

Place the probes on either side of the diode, note the readout, and then switch their position to the opposite. Only one side should read the same/close to the reading that you get when you touch the probes directly together.

If both directions read similar (open, usually close to 0) Then that TVS needs to be removed.

You do not need to replace the TVs, just keep in mind that the power protection is now gone, and if another over voltage occurs then bad things can happen.

Check both the 12v and 5v TVS, one side should be open, the other should not, and remove the damaged ones.

*Edit* and yes, it is a T8
 

Mir96TA

Golden Member
Oct 21, 2002
1,950
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actually small who caused the Puff of smoke, I saw when it was puffed the Smoke, Even through I kill the power to the computer right away.... But who my imidate could be interninty
Now if the Diode is bad what shall I can do ?
I can't even the read that SMT Diode
 

Russwinters

Senior member
Jul 31, 2009
409
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No need to replace, just remove.

you can use a heatgun@500F to heat them up, shouldnt take too long.

Mind the plastic though, you can use aluminum foil to protect it

Use tweezers too apply pulling force while heated, be sure to let the board cool down after removing.


First confirm that they are the issue (Read at or near 0 on diode checker, both ways)
 

Mir96TA

Golden Member
Oct 21, 2002
1,950
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I will Russwinters, However if I just removed it, as you said I wouldn't have any protection for the PCB.
Wouldn't it would be like fu(king a chic and hopping she won't get pregenet ;)
 

RebateMonger

Elite Member
Dec 24, 2005
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Russwinters,

If I understand what you are saying, there are two overvoltage protection devices (Transient Voltage Suppression diodes) on the Seagate PCB (one for the 12V supply and one for the 5V supply), that can kick in if the PCB board is overvoltaged? When they fail they cause either a momentary or a permanent short between the power rails and ground. The permanence depends on how "bad" the transient is.

You are proposing removing the failed diode so that there's no longer a short. Right?

Do you have any estimate of what percentage of disk failures are caused by TVS shorts? And are there brands of disks that are more prone to TVS shorts causing disk failure?

I'm guessing the symptom of a TVS-related failure would be a sudden, no-warning, complete disk failure, with the power supply shutting down at the same time? If you plug a failed disk back in, it, presumably, will shut down the power supply immediately?
 
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Mir96TA

Golden Member
Oct 21, 2002
1,950
37
91
O $hit I found the Problem!
I was using this as an Ext Drive and PWR comming from EXT E-Sata port where it also had a Pwr connection (Old Molex) where I have converter to Sata PWR plug.
On Molex side Molex to Sata converter was bareley plugged in BUT BACK WORD!
Either I some did this or My 3 Old son was checking out the wiring!
 

Russwinters

Senior member
Jul 31, 2009
409
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Russwinters,

If I understand what you are saying, there are two overvoltage protection devices (Transient Voltage Suppression diodes) on the Seagate PCB (one for the 12V supply and one for the 5V supply), that can kick in if the PCB board is overvoltaged? When they fail they cause either a momentary or a permanent short between the power rails and ground. The permanence depends on how "bad" the transient is.

You are proposing removing the failed diode so that there's no longer a short. Right?

Do you have any estimate of what percentage of disk failures are caused by TVS shorts? And are there brands of disks that are more prone to TVS shorts causing disk failure?

I'm guessing the symptom of a TVS-related failure would be a sudden, no-warning, complete disk failure, with the power supply shutting down at the same time? If you plug a failed disk back in, it, presumably, will shut down the power supply immediately?

Basically, they absorb overvoltage and convert it to heat energy, acting as a filter, but if the overvoltage is too great, they cannot hold the heat energy in and pop, dead TVS. In this case the TVS are not physically damaged (cracked, etc) so i doubt the overvoltage is too bad. Luckily many of the really important stuff on the PCB uses 3.3 volts and so it is pretty difficult for the main components to get cooked if the TVS doesn't do it's job.

basically if your TVS cooks, you can remove it, but now your "filter" is gone. So make sure you have it on a very same power source, and pull your data off, then replace the drive. (you COULD repair it and use it, but i wouldn't recommend it. Kind of like if your engine exploded, and you repaired it...would you put you kid (data) back in the car and drive it?


This type of failure is pretty much 100% non brand specific. It's always user error/uncontrolled event like bad wiring, lightning, etc.

notebook drives don't have tvs, they just use fuse, so you have to replace or jump the fuse on notebook drives. (i have seen a FEW notebook drives with tvs, like 2...ever, and i do ALOT of recoveries...~500 year at least.)
 

Russwinters

Senior member
Jul 31, 2009
409
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O $hit I found the Problem!
I was using this as an Ext Drive and PWR comming from EXT E-Sata port where it also had a Pwr connection (Old Molex) where I have converter to Sata PWR plug.
On Molex side Molex to Sata converter was bareley plugged in BUT BACK WORD!
Either I some did this or My 3 Old son was checking out the wiring!

My money is on the smaller (5v) being the dead one then, the 12v TVS can absorb the 5v current easily, but the 5v TVS cannot withstand over twice it's rated current.
 

Mir96TA

Golden Member
Oct 21, 2002
1,950
37
91
My money is on the smaller (5v) being the dead one then, the 12v TVS can absorb the 5v current easily, but the 5v TVS cannot withstand over twice it's rated current.

So where in the world I found the part # and where I can buy it from ?
 

Mir96TA

Golden Member
Oct 21, 2002
1,950
37
91
Do not have Diode testing feature, Man I miss my hobby toy 150 in One
I can't belive I have paid over $40 Buck for this Digital Multimeter with LCD read out
It has following feature
Auto Ranging with
Manual Ranging Override
- Makes the multimeter easy and safe to use.

Overload Indications - Indicates an overrange or over-maximum
value on the display and sounds
warning tones to alert you of voltage,
current, or resistance measurements
that exceed a selected range.

Effective Overload and
Transient Protection - Helps protect your multimeter from
overvoltage in most ranges.

Full Auto-Polarity Operation - Protects your multimeter and gives
valid measurements even when you
connect the leads in reverse polarity.

Data Hold Function - Freezes the display so you can keep
the reading on the display even after
you disconnect the probes.
 

Russwinters

Senior member
Jul 31, 2009
409
0
0
Do not have Diode testing feature, Man I miss my hobby toy 150 in One
I can't belive I have paid over $40 Buck for this Digital Multimeter with LCD read out
It has following feature
Auto Ranging with
Manual Ranging Override
- Makes the multimeter easy and safe to use.

Overload Indications - Indicates an overrange or over-maximum
value on the display and sounds
warning tones to alert you of voltage,
current, or resistance measurements
that exceed a selected range.

Effective Overload and
Transient Protection - Helps protect your multimeter from
overvoltage in most ranges.

Full Auto-Polarity Operation - Protects your multimeter and gives
valid measurements even when you
connect the leads in reverse polarity.

Data Hold Function - Freezes the display so you can keep
the reading on the display even after
you disconnect the probes.

If you do not have diode checking, but have auto range, you can use the OHM meter to check the TVS as well. Make sure it is set to low-OHM. The diode checker is similar to OHM meter, but alittle safer for small electronics. Check for the same thing, if it is close to 0 OHM each direction it is dead, remove it, and get your data back. Then get a new drive.

Enjoy!
 

Mir96TA

Golden Member
Oct 21, 2002
1,950
37
91
Holy Gocomoly GOD
I took out the that 3.3 TVS (little push from my pinky finger) it fell off.
Pluged it in.
Son of GUN! HDD worked
I booted off that HDD and posting off it.
Thank you Russwinters! ():)
Now if I want to fixt that TVs Where I can the part number ? or buy it from
Also where I can find out the oriention of the the Diode (I know they go only one way)
BTW Where did you learn about these things ?
Again Thank you so much:awe:
Now HDD appears little bit more snappier
Check out the results
When it was running normally
HDTune.jpg

After TVS removed

TVSRemoved.jpg

Strange and odd right ?
 
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Russwinters

Senior member
Jul 31, 2009
409
0
0
Part number is on the diode


orientation usually there is a key, or you need to look at a working PCB and match it up


Self taught, was trained by Dmitry Postrigan, owner of Atola Technologies, and creator of MHDD, AFF Repair station, and other freeware tools, and also the creator of the Atola Insight. He trained me for ~1 Month and then I have been learning on my own for the past few years.

My company does offer training $1000 for 2 days; it is meant to give you a "kick start" into Data recovery


Removing TVS has no effect on performance, other then losing power protection, which is negative. Replace the drive immediately.

Likely the reason it is performing better is the temperature, HDD typically perform reads better at lower temperatures (higher temperatures cause the heads to fly closer to the platters, which is alittle worse for reading, but better for writing (HDD actually have a "heater" on the headstack to heat themselves up for performing write operations)
 
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