DR60: bad frames (drop-outs)

[Piotr Wozniacki]

I've been using the DR60 for some time now with great satisfaction. Today however, for the first time, I noticed what I thought shouldn't happen with such an expensive device: a drop-out! Yes, some 12 frames are bad (displayed red when I scroll through time-line in Premiere; Vegas won't even read the clip - it hangs building peaks). With Nero Showtime, I can play the clip but there is evident choking and makroblockiness for around half a second.

I played back the clip directly from the drive, so it didn't happen during firewire copying to my PC. What can be the reason? Bad clusters on the drive (hopefully not; 12 frames is just the lenght of the PAL GOP)? Intermittent firewire cable not contacting in either the camera or the drive?

Any thoughts welcome. BTW, is it safe to perform a low level formatting and re-partitioning of the drive without rendering it useless? I noticed that apart from the USER and VIDEO partitions, there is some 32MB slack at the very end of the drive; I'm tempted to re-partition and create just the single VIDEO partition covering the whole drive, but will it work?

[John Bosco Jr.]

Originally Posted by Piotr Wozniacki

I've been using the DR60 for some time now with great satisfaction. Today however, for the first time, I noticed what I thought shouldn't happen with such an expensive device: a drop-out! Yes, some 12 frames are bad (displayed red when I scroll through time-line in Premiere; Vegas won't even read the clip - it hangs building peaks). With Nero Showtime, I can play the clip but there is evident choking and makroblockiness for around half a second.

I played back the clip directly from the drive, so it didn't happen during firewire copying to my PC. What can be the reason? Bad clusters on the drive (hopefully not; 12 frames is just the lenght of the PAL GOP)? Intermittent firewire cable not contacting in either the camera or the drive?

Any thoughts welcome. BTW, is it safe to perform a low level formatting and re-partitioning of the drive without rendering it useless? I noticed that apart from the USER and VIDEO partitions, there is some 32MB slack at the very end of the drive; I'm tempted to re-partition and create just the single VIDEO partition covering the whole drive, but will it work?

This sounds like bad blocks on the drive, but it could very well be that a vibration or some sort of shock interupted the recorded signal briefly. Did you notice anything unusual when you were recording? Did you simultaneously record to tape? If you did, you can see if the error happened in the same area. That would indicate that it isn't an issue with your drive. As far as maintenance and/or restriping the drive, I would first seek advice from a Sony sevice technician.

[Piotr Wozniacki]

No, I wasn't recording to tape simultaneously. Well, I formatted the drive (from its own menu), and run the chkdsk command on it - no bad setors found. I hope it won't happen again; if you ask if anything unusual happened I must say - no, not during the recording. But when I was copying to my PC (drag'n'drop method), I did inadvertently start copying something elso from the PC to the DR60 while the clip in question was copying the other way. Perhaps that was when something went wrong? I certainly hope so!

[John Bosco Jr.]

Originally Posted by Piotr Wozniacki

No, I wasn't recording to tape simultaneously. Well, I formatted the drive (from its own menu), and run the chkdsk command on it - no bad setors found. I hope it won't happen again; if you ask if anything unusual happened I must say - no, not during the recording. But when I was copying to my PC (drag'n'drop method), I did inadvertently start copying something elso from the PC to the DR60 while the clip in question was copying the other way. Perhaps that was when something went wrong? I certainly hope so!

That very well could be the problem. The clip, as it was being offloaded to your PC, probably got corrupted because of the reverse inadvertent copying to the DR60. I assume the problem was not noticed prior to digitizing the clips to you PC. Considering the disk reported "no bad sectors," I think you're good to go. I'll keep my fingers crossed. Best of luck.

[Piotr Wozniacki]

Originally Posted by John Bosco Jr.

That very well could be the problem. The clip, as it was being offloaded to your PC, probably got corrupted because of the reverse inadvertent copying to the DR60. I assume the problem was not noticed prior to digitizing the clips to you PC. Considering the disk reported "no bad sectors," I think you're good to go. I'll keep my fingers crossed. Best of luck.

Thanks John; I'll keep all of you posted. I certainly hope this was a one-off!

[Piotr Wozniacki]

As promised, an update. A file corruption happened to me again; this time however I managed to pin-point the problem: Diskeeper (defragmenting Windows extension) that's working in the backgroud started its job on the DR60 the moment it was plugged in. I don't know why, but somehow the checkbox "automatically defragment new volumes" got checked... Anyway, not being aware of Diskeeper activity, I started the usual drag'n'dropping of m2t files; it took ages so I cancelled the process (that was silly, I know). And probably this is when it went wrong: a couple of subfolders vanished from the DR60! I run chkdsk, and it reported cross-linking; files got truncated and I only managed to restore some clips (fortunately, this wasn't a crucial shooting, anyway).

Conclusions:

- if you have software like Diskeeper, configure it so that it doesn't try to defrag the files on your DR60.

- more general consideration: how much corruption-proof is the m2t format, stored on a HDD? Of course, when I shoot something critical, I use tape as well so I always have the archives, however I noticed that some of my older clips on the PC's HDD (don't even remember if captured from tape or copied from DR60) do show some bad frames which weren't there before... Chkdsk or scandisk don't show any problems, so how can it happen?