# Procedure for Repairing Bad HD Sectors -- R15



## troop72 (Aug 23, 2006)

My R15 hard drive had developed bad sectors most likely due to overheating.
(To prevent overheating see carl6's post on re-wiring your fan to run continuously 
ref: http://www.dbstalk.com/showthread.php?t=59928&highlight=carl6+fan )

I had spotted a post by javacado about repairing bad sectors but I was not interested in purchasing new software. 
ref: http://www.dbstalk.com/showthread.php?t=61887&highlight=SpinRite+javacado

I was able to repair my drive using the following procedure:

*CAUTION: *You should have a basic knowledge of electronics and PC hardware and you should know and always follow the safety procedures for working on these devices.

*CAUTION: *This procedure *will* delete *all *existing information on your drive, including all recorded programs and showcases.

START

1. Disconnect the AC power cord from the R15

2. Remove cover. Remove the hard drive from the R15 (power connector, ribbon cable, and four screws)

3. Connect the R15 drive to an Intel PC chassis as the *only* hard drive. Note: I used an older Gateway PC. I set the drive jumpers to MASTER but your BIOS may require a different setting.

4. Boot the PC from the Windows XP installation CD-ROM.

5. Enter the Windows Recovery Console. At the "Welcome to Setup" screen, press F10 or press 'R" to repair.

6. Run the Windows XP CHKDSK utility to find and flag bad sectors

CHKDSK C: /R

The /r option locates bad sectors and recovers readable information. This can take two hours or more - be patient.

7. Power off the PC and remove the hard drive

8. Reinstall the hard drive in the R15 (power connector, ribbon cable, and four screws)

9. Replace Cover. Reconnect the AC power cord, power up the R15, and format the disk using the DOWN ARROW/REC method. (See R15 forum for detailed instructions...)

END

>>>>>

DOESN'T THE REFORMAT UNDO EVERYTHING CHKDSK FIXED?
I am not an internals guy but apparently it doesn't. CHKDSK probably doesn't fully understand the format in the R15 drive to begin with.

Hard Drives come with spare sectors and the drive firmware is supposed to handle most of the bad sector marking and sparing. My theory is that when CHKDSK reads every sector it forces the drive firmware to re-map the bad sectors to good spares.

Experts should feel free to correct me or explain it more clearly for the benefit of all of us.

>>>>

WHAT DOES CHKDSK DO?
More complete information on chkdsk is available here for the curious.
http://support.microsoft.com/kb/314835/EN-US/


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## Wolffpack (Jul 29, 2003)

If you did a DOWN ARROW/REC after your CHKDSK that negated your CHKDSK. I wouldn't recommend running CHKDSK on any R15 drive as the R15 doesn't have a standard FAT32 file system. It has a hybrid system that allows for larger files.

If you indeed had bad sectors on your drive the only approach I would take is to run the diags supplied by the drive manufacturer. In my case it's a Seagate 160GB drive. Download the Seagate diags and run a low level scan on the drive. That will flag any sectors as bad and update the bad track table. CHKDSK does not work at the hardware level, it works at the filesystem level.



> DOESN'T THE REFORMAT UNDO EVERYTHING CHKDSK FIXED?
> I am not an internals guy but apparently it doesn't. CHKDSK probably doesn't fully understand the format in the R15 drive to begin with.


Yes, the reformat will undo what CHKDSK did. If you look at a R15 drive in your PC you will see that while it may have no data on it, it is 100% used. That's what the enhanced FAT32 filesystem does and why Windows can't read/write to that filesystem dependably.



> Hard Drives come with spare sectors and the drive firmware is supposed to handle most of the bad sector marking and sparing. My theory is that when CHKDSK reads every sector it forces the drive firmware to re-map the bad sectors to good spares.


Correct and incorrect. Yes the drive firmware will flag sectors as bad and not even let the OS know about those sectors. The drives themselves remap a bad sector to one of the good spare sectors. But CHKDSK doesn't operate at the firmware level. It operates at the filesystem level. The only way to get bad sectors mapped into the bad track table is via the manufacturers diagnostic utilities.


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## harsh (Jun 15, 2003)

Formatting the drive should be able to identify and mark bad sectors at the OS level. That assumes that they haven't already been replaced by the drive itself. Running a S.M.A.R.T. diagnostic on the drive is probably a good idea to see if the hardware is failing. If it seems to be okay, then it is likely that the operating system is wetting its bed.


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## skaeight (Jan 15, 2004)

How did you know you had bad sectors? Heat would most likely not cause bad sectors. I think that procedure you described is way more than should be necessary with this machine. Just call up d* and tell them to replace the box. As Wolf said, the down+rec will completely wipe out anything the chkdsk did. All chkdsk does is mark the sectors bad in the FAT table, which would be wiped out with the down+rec.


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## troop72 (Aug 23, 2006)

skaeight - Maybe it wasn't heat, but disk equipment can do weird things when it is hot.
How did I know I had bad sectors? Am I absolutely certain? No. But I have been working with disk drives since 1980 when a 300 MB unit required eleven 20 inch platters with 19 recordable surfaces, plus a timing surface, and was as big as a dishwasher. I can hear a disk drive doing the "read/write error shuffle" from across the room :grin:

Wolffpack : Yes I understand that CHKDSK is primarily a file system level tool

However CHKDSK _does_ attempt to read every sector with the /r option. Maybe it does that by attempting to ready every file system cluster, I dunno. All I was theorizing was that just _attempting_ to read the sectors that were bad caused the firmware to do its magic.

I do like the idea of running mfgr's disgnostics instead, however, and I will do that if I have that unfortunate opportunity. But as of right now I have spooled up over 30 hours of recordings without an issue...

Now if only the software bugs would go away...


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## gomezma1 (Mar 28, 2006)

I disconnect mine every nite. Why have the unit still run in stand-by wasting energy and wear and tear on unit. If there are updates , it will upload when it reprograms. It works for me and have done it since 98. Plus you don't have to hear the fan run.


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## Wolffpack (Jul 29, 2003)

troop72 said:


> However CHKDSK _does_ attempt to read every sector with the /r option. Maybe it does that by attempting to ready every file system cluster, I dunno. All I was theorizing was that just _attempting_ to read the sectors that were bad caused the firmware to do its magic.


Just for reference, neither Windows or SUSE Linux can read all of the "clusters/sectors" on the R15's FAT32 filesystem. Because it's not a legal FAT32 filesystem.


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## pentium101 (Nov 19, 2005)

Wolffpack said:


> Just for reference, neither Windows or SUSE Linux can read all of the "clusters/sectors" on the R15's FAT32 filesystem. Because it's not a legal FAT32 filesystem.


I believe that you can if reading/writing the drive using LBA addressing.

Even after performing a low-level format, which cannot truly be done on an EIDE drive after it leaves the factory, you can still access it using LBA.


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## psweig (Feb 4, 2006)

troop72 said:


> skaeight - Maybe it wasn't heat, but disk equipment can do weird things when it is hot.
> How did I know I had bad sectors? Am I absolutely certain? No. But I have been working with disk drives since 1980 when a 300 MB unit required eleven 20 inch platters with 19 recordable surfaces, plus a timing surface, and was as big as a dishwasher. I can hear a disk drive doing the "read/write error shuffle" from across the room :grin:
> 
> Wolffpack : Yes I understand that CHKDSK is primarily a file system level tool
> ...


This really brought back memories. That read/write shuffle is written on my brain. Oh, for the old days, when all you had to do was call the firmware at a specific address and you could low level the drive.:icon_band


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## skaeight (Jan 15, 2004)

troop72 said:


> skaeight - Maybe it wasn't heat, but disk equipment can do weird things when it is hot.
> How did I know I had bad sectors? Am I absolutely certain? No. But I have been working with disk drives since 1980 when a 300 MB unit required eleven 20 inch platters with 19 recordable surfaces, plus a timing surface, and was as big as a dishwasher. I can hear a disk drive doing the "read/write error shuffle" from across the room :grin:


I know what you're talking about, drives make bad noises when they fail. However you really should just call D* and get a replacement unit. With the new lease program, they'll replace it at no charge. They really don't want you opening the units up.

Also, from personal expercience, I've found that if a drive is infact failing, there is no disk utility out there that will prevent it from eventually completely failing and at that point you'll lose everything you had on the disk anyways. So at this point you might as well take steps to get a replacement.


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## Wolffpack (Jul 29, 2003)

pentium101 said:


> I believe that you can if reading/writing the drive using LBA addressing.
> 
> Even after performing a low-level format, which cannot truly be done on an EIDE drive after it leaves the factory, you can still access it using LBA.


That's correct, I was referring to going through the filesystem calls. The raw data can be read but the file/directory structure cannot be followed properly.


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## troop72 (Aug 23, 2006)

skaeight

I own my unit, have no service period committment, and am not interested in a 2 year lease...

Given the known bugs/issues with the R15 I am more likely to repair, buy a used unit off of ebay, or switch to dish than commit to the R15 right now.
(Plus I will be going HD in less than 2 years...)

For those who have a leased unit your advice is SPOT ON!!


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## skaeight (Jan 15, 2004)

troop72 said:


> skaeight
> 
> I own my unit, have no service period committment, and am not interested in a 2 year lease...
> 
> ...


Good luck then. If it does die, you can always just buy a 160GB drive and install it and it will be good as new. However, I'm willing to bet a new R15 from d* would be cheaper (esp since they're actually giving them away for free now, that's how I got mine.)


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## Halo (Jan 13, 2006)

Before about a month ago my R15 was pretty stable- maybe 4 or 5 hangs in the previous 6 months. Then I started getting occasional 'glitchy' video/audio which would usually result in a completely frozen R15. Very annoying because if a recording was happening when a freeze occured that recording would be deleted with a reset.

I mistakenly thought this was just a more severe version of the 'black screen' bug that started with 10C8. It turns out my HD had two bad sectors. What made the problem worse was that I had about 90-95% full and I think the bad sectors were in the free area, so I was hitting those bad sectors frequently.

The SeaTools utility found and fixed the bad sectors. No reformatting needed. All my programs are still there. It's not hard to do this, maybe 5 minutes to remove the HD from the R15, another 5 to put in into the PC, and an hour to run Seatools for the whole drive.

A sector check/fix _should_ be part of the R15 background process. Failing that, the R15 should be able to handle a bad sector with just a slight video glitch instead of freezing up entirely.


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## Bobman (Jan 3, 2006)

gomezma1 said:


> Why have the unit still run in stand-by wasting energy and wear and tear on unit.


Why ? So it can still record things, do its housecleaning, organize the TDL, download VOD and updates, etc....
With the R-15, the fan does not run constantly like DirecTiVos, so fan noise is never an issue.

Your probably only saving pennies a month at best and what you think is saving wear and tear is actually causing more as its the starting up of electronics that are the hardest on them.


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