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Weird situation with bad sectors on ST-225

twolazy

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So I am having a weird situation going on... I recently pulled out my old ST-225. I spun it up now and then ever year just to keep the heads from sticking.

Anywho... So when I went to try to read the data, the drive refused to allow me to even see the fat table. So figuring whatever data was gone, I LL formatted it a few times. Now here's where it gets interesting...

So after 2nd and 3rd format, the drive showed a bunch of bad sectors, around 200kb worth. So I pulled out spinrite and did a full scan. Each time I ran the scan it showed a few new bad sectors. Growing frustrated I formatted it again. Now its showing a weird behavior. I'll run spinrite and have it repair bad sectors. The drive usually will fix EVERY sector. Then running norton speedisk, I'll run a scan , and indeed it finds 0 bad sectors till I reboot. After reboot it randomly finds bad sectors, yet spinrite will not find them usually. I'm scratching my head here. I don't understand how the sectors are repaired, then randomly go bad again.

Anyone have any advice? It almost seems random. Usually a reboot makes them come back, sometimes the drive works great till I power down after parking the head. Are the sectors perhaps marginal? Perhaps there is dust in the drive?
 
Fyi, While I like spinrite myself. The whole "repair bad sectors" isn't a reliable thing, never has been. Just like how it may not see the factory defined bad sectors as bad... You're safe bet is to run without repair (leave bad bad) and run a good LLF when the drive is at temp then let it scan (not repairing) at max patterns. (or use the defect scanner in sstor same way).
 
Are you performing the LLF once the drive has come up to temp, as per Seagate's instructions?
Certainly important. Always make sure the drive is running for some time before doing LFF.

The whole "repair bad sectors" isn't a reliable thing, never has been.
True. It probably tries to repair the sectors that were marked bad from the factory. These can not be repaired. If they could, they would not on the factory-defects list.

Format it as often as needed until no new bad sectors appear. Also make sure it found all from the factory-defects list written on the drive.
 
Are you performing the LLF once the drive has come up to temp, as per Seagate's instructions?
Yes, I let the drive run a good hour before I try to do anything with it, just to rule out thermal expansion.

Fyi, While I like spinrite myself. The whole "repair bad sectors" isn't a reliable thing, never has been. Just like how it may not see the factory defined bad sectors as bad... You're safe bet is to run without repair (leave bad bad) and run a good LLF when the drive is at temp then let it scan (not repairing) at max patterns. (or use the defect scanner in sstor same way).
I'm thinking along the lines you are. Even though spinrite says the sectors are repaired, they might just barely pass an ECC check. Whats weird is each time, other then 2 sectors I'm pretty sure are bad, most rest are random in the first 2mb of the drive.

Maybe I should LLF the drive again...
 
Certainly important. Always make sure the drive is running for some time before doing LFF.


True. It probably tries to repair the sectors that were marked bad from the factory. These can not be repaired. If they could, they would not on the factory-defects list.

Format it as often as needed until no new bad sectors appear. Also make sure it found all from the factory-defects list written on the drive.

Well the label it was shipped with from the factory has nothing listed as defects. I'm thinking ill try formatting it a couple more times and if the bad sectors keep appearing, I guess I can just partition around them.


I will also say, that the card is at a weird address, so the debug command for the WD1003-WAH controller doesn't work. So I am using the built in hard disk utility in AMIBios. I know its not located at C8000 but at F0000 for some weird reason. Haven't been bothered to dig out a manual and change jumpers.
 
Swap the cables. Make sure they are not wrapping around anything electrical.

Had something similar happen to me, and it was the darn cable. Not sure exactly why, but it acted like the data cable was somehow getting "noise" in the signal. It would work, but random bad sectors.
 
Hrm maybe you are onto something here. Didn't think about the cable. I made them myself, and was super careful... I'll take off the control cable this evening and give it a good look, maybe swap it out with an old floppy cable just to rule it out. I am assuming you mean the control cable, aka the bigger one.
 
No, in this case, the smaller data cable would be the suspect one. That is where the raw data read and written goes through. Random noise on that cable could cause random read/write errors. Problems with the control cable would be things like failing to find track zero, no ready signal, or not seeking.

Although I did have a hard drive once that gave random errors that came and went, that as it turned out, was due to metallic dust moving around as the head ground in to the platter... not much that can be done if that is the issue.

Also, BTW, sectors that are filled with zeros are easier for a controller to read than a sector with random data. As a result, it is common for tools like Norton Disk Test to show fewer errors on a freshly formatted hard drive than spinrite's pattern testing.
 
I guess if swapping the cable and its the same, I'll try opening it up and blowing it out with my air compressor. I'm thinking along those lines myself, either dust or something is in the drive. Never encountered this problem before with a MFM disk. The filter does look a little crusty.
 
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back when i was using an st225 still pretty regularly.. Up until the eatly 1990s. i had good luck recovering bad sectors witb LLF and utils. I used to LLF twice a year back then.

And maybe its jusy my experience but the marked bad sectors on the sector map sticker on mfm and rll drives I have never found to be accurate in most cases.
 
I don't trust spinrite at all for bad block diagnosis. Norton Utilities/Norton Disk Doctor for DOS was at the time very well respected.
 
I have to wonder if there's a cap issue going on... A friend just fixed a couple of the old TRS-80 external hard drives and there was a PLL circuit with a bad cap on each.
 
Thanks again NeXT. You hit it right on the head. So I started using Norton Disk Doctor to scan, and didnt repair sectors. Seems Spinrite kept marking them as correctable. Now the drive has a bunch of bad single sectors but doesn't seem to be spreading or finding new ones anymore.

Shame, the drive wasn't used much when I stored it away so many years ago. Guess that is how it goes with these old drives. For now I am happy and drive seems to be working great after a defrag. Still has the be the quietest ST-225 I ever owned!

Guess rule of thumb here is don't trust Spinrite and recoverable/correctable sectors.

Now to finish the keyboard repair thread for the Compaq Portable, so I have a fully working machine, and find an 8 bit MFM card. Was the goal of this in the end.
 
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Spinrite always felt like one of those miracle programs that tried to save money by buying you time, but it was $40 at Egghead. It's like Connectix Ram Doubler serving to hold you over a few more months until you caved and just bought more ram.
I don't trust it. If a sector is failing there's nothing a piece of software can do to bring it back. It will just fail again because it's a physical media failure.
 
I have successfully used Spinrite for data recovery in the past. Where it "repaired" the drive long enough for me to copy files off. So I think it's useful for that. $40 to get your files back is well worth it. I agree the marketing goes too far and is misleading about what it can actually do.
 
There is a write up on Winworld detailing what Spinrite can and can not do.


It does have a habit of returning "weak" sectors to active use, so one should always consider if they should disable Spinrite's ability to do that.
 
Spinrite always felt like one of those miracle programs that tried to save money by buying you time, but it was $40 at Egghead. It's like Connectix Ram Doubler serving to hold you over a few more months until you caved and just bought more ram.
I don't trust it. If a sector is failing there's nothing a piece of software can do to bring it back. It will just fail again because it's a physical media failure.
Agreed. I use SpeedStor for LLF and bad block detection/lockout, as well as exercising new-to-me drives or ones that have sat a long time. The SpeedStor seek test is great for getting head positioning mechanisms freed up and going again.
 
When I had a drive do this behavior I found that during the “behavior “ the drive was spinning slightly slower than it’s rated rpm

Booting off a floppy, parking the drive and waiting 5-10 minutes usually “fixed” it
 
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