I have a possible stiction on a Hitachi Deskstar 250GB 3.5inch HDS722525VLAT80.

BIOS/motherboard doesn't recognize the drive, and the drive does not spin up, and there is no sound. I've tried tapping the drive sideways, freezing & tapping, and rotating (snapping wrist) laterally to free possible stiction, but no go.

Ohm readings taken directly from the motor (I don't know which is ground, so I arbitrarily numbered the leads 1 thru 4, from left to right while facing the bottom of the drive upright):

1-2: 1.8
1-3: 1.8
1-4: 1.8

2-3: 3.2
2-4: 3.2
3-4: 3.2

Does the above show a good motor?




The PCB was fried (power surge), and I've replaced the PCB twice with donor boards from sellers who solicit on this board, transferred both L76R (U5) and SST (U7) chips to the donor, and was only able to spin up once. I disconnected the power from the HD, and later when I tried reconnecting, the drive did not spin up.

If there is stiction, should BIOS recognize the drive? If the cause is stiction, and if tapping, snapping, freezing doesn't work, then do I need to open the drive and move the head?

Also, I plan to try to locate yet another donor PCB, and this time ONLY move the U5 L76R, and NOT move the U7 SST chip. So please let me know if anyone has a donor board.

(This time, I'll only be purchasing from a U.S. source, because I've purchased from a foreign source before and I received a banged up PCB with multiple damage, including a broken-off surface mount resistor, and the customer service was basically out of this world--and not in a good way.)

No it's not stiction, it's a fried HSA. OR there is something really wrong with the PCB (my bet is on HSA).
With the right tool it is easy.

Agree.

The fact that the drive has cooked at least one PCB indicates the drive has much more serious internal issues.

My money is on a fried preamp.

Not DIY

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Is this for real?
You say it had a power surge & as you can see the pcb had physical damage so how did you jump to stiction as the fault after swapping pcb? 2.5" drives suffer more from stiction less likely in 3.5" drives.
Your drive probably has more interal damage due to the power surge ie damaged preamp. To confirm this it would need to be sent to a pro for inspection.

Proper diagnosis is required & your guessing. Also you say you have freezed the drive? Another bad move. Stop doing what your doing as your putting your data at risk. If your data is important enough to warrant the cost then seek a dr pro to recover your data. Sorry to be blunt but you dont have the tools, specialist equipment, knowledge or experience to fix this. Not DIY.

Loki

Thanks for the replies. Without discounting your bets, the reason why I think it's stiction is because I disconnected the power abruptly while there were head seeking noises going on inside.

As for the burnt pcb, that occurred as a result of a power surge. I've so far gone through two donor pcb's, but the supplier provided dubious boards (not matching pcb revision, broken off resistor, etc...).

Also, I read on this thread that replacing the U7 will cause the drive to NOT start up. And I DID move the U7 as well as U5, in both cases. So, my *hope* was that it was either stiction, or I shouldn't have moved U7, or the P/N,PCB,MLC didn't match.

Any chance if you guys could help me identify whether it is internal (head stack vs preamp)? Any multimeter tests I can perform? And what about the lack of BIOS recognition?

Thank you

Personally I can't help, I have an allergy to multimeters...
All the symptoms lead to HSA failure, but it is also probable that you have toasted the pcbs. Sorry but the diagnose must be carried out differently - you don't have a single certainty about pcb functionality, HSA, rom and eeprom content and most of all you don't know how Hitachi work. Out of curiosity, where did you exactly read about pcb and moving chips etc. ?

I learned about swapping pcb's and nvram's from reading this forum. I actually successfully revived two other WD's with donor boards and nvram transplants, but this Hitachi refuses to cooperate. I'm thinking about trying another donor board, but this time with one with more matching numbers and only moving U5.

In this person's experience, a donor pcb and nvram move brought back to life a drive that didn't spin up (hitachi-hds722020ala330-pcb-swap-support-t21097.html), so I can't see why the diagnosis would necessarily jump the flow to HSA or preamp, given that my donor pcb's were of suspect quality and match, and I could also have botched the transplants by moving U7.

I do understand, though, that without special diagnostic equipment, I'm just making guesses. If anyone with specific Hitachi knowledge would at least let me know if my ohm readings from the motor lead to a good motor, whether HSA/preamp failure on this drive would prevent spin up, and whether BIOS should recognize the drive without spin, I'd appreciate it.

I am for real, but I should ask whether you are, or are you just shilling and scaring people into turning over their drives to "professionals" who mostly send the drive out to subs and pretend that they fixed it.

I appreciate your comments, but do read the original post carefully before doling out unnecessary caution. The physical damage prompted a donor with nvram transplant. That resulted in a spinning drive, but I quickly disconnected the power during seek. Later, when I reconnected, there was no more spin, hence the stiction hypothesis. That donor pcb didn't cook, either, as pcimage seemed to imply. What is more curious is why you are jumping to preamp. I'm not ruling out anything, but you've already narrowed the diagnosis. Curious. Care to elaborate as opposed to mock?

Your here asking for advice but dont like the advice given. Thats fine take it or leave it, its your data. I know more than to put a hdd in a freezer but hey you seem to know better.
You will find that lots of posts give out cautions & to seek a pro when diy is not an option. This is becuase we have more experience & knowledge than the poster & dont want them making it worse & costing more for a recovery If they decide to go down that route. Its got nothing to do with making a quick buck if that was the case then we wouldnt give our free time on this forum.

Yes im for real i have so far spent over $50,000 & have been to Russia for specialist training on the pc3000 udma etc. Have you? NO.

The logic for leaning towards the preamp is due to the location and component that was damaged. If it was just a simple tvs fault then you would not of had the damage you got on the chip as the tvs would of done its job. Also a damaged preamp can damage your replacement pcb which is likely as they now dont work. This is where we have spent years learning and spending time & money gaining experience.


I wish you all the best in your recovery but I will not be commenting on your post any further.

Loki

I can't say if you have killed the replacement pcbs or not but there is an easy check you can do yourself with a GOOD pcb.

Disconnect the pcb from the hda but leave the ribbon cable connected.
Now connect the molex power connector and apply power.
So does it spin or not?

If it spins then stiction it is not and probably the motor is good.

So if you get to this point it would seem the preamp is likely to be faulty.

Remember when that particular ic is damaged/splattered as shown in the photo there is always a likelihood the preamp will be destroyed at the same time!

When people will assume that a professional with a tootpick and a screwdriver can do what average joe with JPL / NASA lab gear can't, will always be too late

Subject: Possible stiction on Hitachi Deskstar 250GB 3.5inch HDS722



dick, thank you for actually reading my post and addressing my questions. I'll look for a good pcb, but it's very difficult to find one where the top 2 numbers match.

To shill posters here to scare new readers into taking their drives straight to costly repairs when the solution could be simple, to new readers who may be contemplating DIY, and to real experts here to actually help:

1. Some have responded to my post by saying that stiction (heads stuck on platters outside of parking zone) is not likely on a 3.5" drive. However, this statement is made without consideration of the particular history of this drive, nor with discussion of logical diagnostic progression.

Notwithstanding the fact that plenty of web searches will dig up stiction on 3.5" drives, and notwithstanding the fact that I removed power during seek, these "experts" move quickly toward the diagnosis of "internal" damage only to be touched by "professionals."

In case some of these resident shillers would like to know, the stiction hypothesis arose as a result of a 20-minute conversation I had at a party in Silicone Valley with a Western Digital forensic engineer regarding my specific drive.

2. With so many possible causes as to why the drive does not spin up, these "take it to your professional" long-time resident alarmist shill posters of hddguru conveniently point all hypotheses to "internal damage," even when provided with a link in my earlier post showing how a DIY repair resolved a non-spinning drive with a pcb replacement: hitachi-hds722020ala330-pcb-swap-support-t21097.html

Furthermore, even though I have provided motor resistance readings, the response I get is "I'm scared of multimeters, but I'm an expert and trust me it's internal" or "I didn't read your post very well, but are you for real or are you an idiot for trying."

Well, I should like to subsidize one's $50K investment with a free lesson. The following image shows a pcb with a splattered ic. This drive this burnt pcb was attached to suffered the same power surge as the Hitachi in this thread, and it was recovered with a donor pcb and nvram move. The drive worked perfectly fine, and it's been running for more than a year running an OS on a spare test computer. Hence, there is no need to jump to HSA or preamp failure conclusions:



3. To all others, please post only if you have constructive information.

Was the operation done at the same party too by a chance ? Just because there is NO "NVRAM" on THIS PCB (if it was the real case)
On EB/BB/Protege' (WD, that are NOT Hitachi) things go VERY DIFFERENTLY when a PCB is fried. Stay sure that if some coincidences occur, beside the combo IC you get the Talon FUBAR. In this case, 99 out of 100 HSA is fried too.



This kind of response in this form exist only in your mind. Don't put in our... fingers words that I did not say (for me, at least):



I said (sorry if you didn't understand but it's not my fault) that I use something else to check FOR SURE motor functionality and everything else (and up today I didn't fry a single PCB that I should repair LATER :S ). It confirm that if you knew how Hitachi work, a lot of questions would have not been asked : if "some abnormality" is detected at power on, depending on type this is exactly what happens OR motor spin up BUT..............................

If you knew a DIFFERENT story about the drive, why not tell it right from the start ? Unless the "intention" about opening the thread was another - and this is what I think.

Those readings look OK.

Pin #1 appears to be the Common terminal, and 2,3, and 4 are the three phases.

The phase-to-common resistances (1.8 ohm) are identical, as are the phase-to-phase resistances (3.2 ohms). The latter are also approximately twice the former. This is what you should be looking for. An inductance test would be better, though.

Your readings would also include the resistances of your probes and selector switch. This appears to be 0.4 ohm (that's what you should see when you touch the probe tips together).

If you wish to measure the voltages on your suspect boards, I would measure the voltages at each of the coils (L1, L2, L3), and transistors Q1 and Q3. AFAICT, L1 and L3 constitute a Cuk converter that provides the -5V supply for the preamp, L2 probably provides the Vcore supply for the MCU, and Q1 and Q3 constitute linear regulators which probably provide the Vio supply for U5, U7, and the SDRAM.

If the supplies are OK, measure the voltages at the motor terminals soon after the drive powers up. If the board is trying to spin the motor, then you should see voltage pulses every few seconds.

Depending on what you find, we can then proceed to measure the preamp terminals.

Edit: I believe I have a very similar board, but no HDD. I should be able to confirm your voltage measurements when I locate it.

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A backup a day keeps DR away.

fzabkar, thank you for the additional info. I'm not an engineer nor a technician, so I'm going to have to take some time to absorb what you said, so please excuse me if I take some time before I post back test results (maybe weeks). But, I will try to figure this out, and come back as soon as I can. It sure seems that your suggestions would help me find out if I've gone as far as I can on this drive as I can before having to take it to a recovery professional.

Btw, you're a great asset to this forum--I've been reading your helpful posts all over this site.

BlackST, I should like to make peace with you. I'm one of those people who will visit this site once or twice in their lifetime to fix fix their drives, whereas you deal of people from all walks of life, including clueless ones like me. And, I know how things get when you've tried to help a thousand thankless newbies.


No. We held cocktails at the party, not soldering irons. I performed the operation myself. I saved 2 WD's this way, all damaged by the same power surge in the same computer as this Hitachi.


I didn't have any "different" story about the drive that I withheld in my original post. I put everything there. Though WD owns Hitachi, the WD engineer I talked with knows nothing about Hitachi's. He merely said that based on subjects he receives from WD's OE clients/customers, stiction does happen if power is lost during seek/write, as the auto-park feature on modern drives doesn't always work. So, I came to this forum to validate his hypothesis.

Anyway, thank you everyone for your input on this drive. And, again, fzabkar, I will try to figure out and understand your tests, and I'll report back in some weeks.

In the mean time, if anyone has a PCB with the first 2 lines of matching numbers, please let me know, as I'd like to have a real good match as opposed to my last 2 donors, so that I can verify the DIY-ability of this drive.