# 722 Hard Drive Failure = Better Picture



## mark722 (Sep 27, 2007)

The hard drive on my 722 failed this last weekend. At first the box would freeze and reboot itself a few times a day, then it completely died. I got the 311 screen "Hard Drive Failure" and a power cord reset didn't help, but I could still watch live TV. What I noticed immediately was that my picture quality dramatically improved. The picture had always been good since I use the HDMI out at 1080i to a Sony HDTV, but this was like the difference between watching a movie on DVD then upgrading to Blu Ray. This may be due to the way the DVR buffers the video to the hard drive. If I could disable the buffering to get a better picture, I would. Ideally, the buffering should only start if you hit the pause button. I'm sure a lot of people like being able to rewind live TV, but there should be an option to disable it. I've got a replacement 722 on the way, but I'll miss the picture quality of my hard drive impaired 722.


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## ZBoomer (Feb 21, 2008)

There is no difference in what you call "buffered" video and live video. The receiver is saving the signal as it comes down from the satellite; there is zero degradation. It's not like an old-school Tivo which digitizes an analog signal and compresses it; it takes the actual digital stream off the satellite and saves it.

Replaying it is the same as when it came down off the dish.

Something else changed in your system, if you saw a better picture when your drive failed.


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## mark722 (Sep 27, 2007)

Actually, the only thing that changed was the hard drive failure. I didn't change any settings on the DVR or TV. The only thing that was reset was the power. I'm not the only one that noticed the picture improvement either. My two rommates also noticed the difference. I'm no expert on the software and hardware design of the 722 DVR, but I would like to know what makes Zboomer so sure that a hard drive failure could not effect the picture quality.


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## Tulsa1 (Oct 15, 2003)

mark722 said:


> Actually, the only thing that changed was the hard drive failure. I didn't change any settings on the DVR or TV. The only thing that was reset was the power. I'm not the only one that noticed the picture improvement either. My two rommates also noticed the difference. I'm no expert on the software and hardware design of the 722 DVR, but I would like to know what makes Zboomer so sure that a hard drive failure could not effect the picture quality.


You are not alone. I witnessed the very same phenomenon when the hard
drive in a 622 died a couple years ago. I lost all DVR functions but live TV
was razor sharp. I had another 622 next to it to compare to and there was no
doubt.


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## dmspen (Dec 1, 2006)

This makes me wonder if there is some type of compression of the input signal when going into the buffer. With the hard drive/buffer out of the picture, you'd get the straight signal coming in.

Interesting.


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## Stewart Vernon (Jan 7, 2005)

It actually seems plausible to me... but not for the reason you might think.

With the DVRs you are pretty much always watching buffered programming... because when you are watching "live" it is still being buffered to the hard drive.

IF you begin having hard drive issues... it could very well initially manifest in some lost bits here and there... and error correction might not be able to handle it... so you might see things like pixelation or stuttering.

Once the hard drive fails and is out of the loop... you'd be watching the live stream live... and not have the hard drive activity interfering anymore.

A properly functioning DVR with a good hard drive shouldn't be distinguishable in terms of picture quality.


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## sigma1914 (Sep 5, 2006)

If this is the case, then do non DVRs give a better picture?


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## P Smith (Jul 25, 2002)

there is no such reading from disk's buffer to produce picture on TV, the processes going simulaniously, but before you press Pause -after that your screen picture/sound making from drive's buffer


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## bnborg (Jun 3, 2005)

If the drive is failing, the DVR would be getting "Drive Not Ready" signals. Depending on how much memory buffer there is, the DVR might attempt to write the block again.

In any case, some of the data will eventually get lost. If the Linux OS is putting higher priority on disk writes versus display output, the data will be lost before it is displayed. This would give you a corrupt picture until it re-synchronizes.


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## harsh (Jun 15, 2003)

It seems like one of the fundamentals of the TiVo lawsuit was that the displayed picture was bouncing off the hard drive.


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## P Smith (Jul 25, 2002)

as you wish ... but 501 is working his own way by design


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## Stewart Vernon (Jan 7, 2005)

sigma1914 said:


> If this is the case, then do non DVRs give a better picture?


Not that I can tell... and no reason that they would.

Think of it another way...

An air conditioner in a car is not required for it to run... but a poorly performing one is more of a drag on the gas mileage than a properly performing one.

While the hard drive is failing... it is still trying to work, and generating errors and retries and tying up CPU cycles.

When it fails, the video might look better now that the failures have stopped.

Get a properly functioning DVR and hard drive again... and the picture quality should be good.


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## [email protected] Network (Jan 6, 2011)

Honest question here so try not to bash me too much. Is it possible that the hard drive failing was creating some sort of noise in the power?

For example, I know that laser devices can cause a back feed of digital noise into the power and create issues with picture. Power conditioners tend to isolate laser devices so they do not interfere with picture via the power cord (dirty power causing the picture distortion). The receivers hard drive might have a similar effect if it is not functioning properly.


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## P Smith (Jul 25, 2002)

Shouldn't ... need to measure in a lab for final answer.


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## [email protected] Network (Jan 6, 2011)

Agreed. Not sure DISH would take kindly to me wrecking a hard drive in the testing room just so I can check picture quality and power noise levels. LOL


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## CABill (Mar 20, 2005)

[email protected] Network said:


> Is it possible that the hard drive failing was creating some sort of noise in the power?


I'd have to say that was possible, and the points Stewart and bnborg mentioned are also valid.

I just wanted to mention that the exact opposite of your point is also possible. A failing power supply can be causing the drive issues. I have an old 501 that finally only did a reboot loop when plugged in. My "solution" was to open it (own it) and power the drive from an external source and now can use the 501. Whether power is messing with the drive or the drive messing with power, it would be best to compare picture quality when the DVR wasn't having issues.


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## Stewart Vernon (Jan 7, 2005)

CABill said:


> A failing power supply can be causing the drive issues.


That's a good point. A failed power supply wouldn't power anything... but one that is failing OR just has trouble under stress could result in power dropping below tolerance anywhere in the system.

I hadn't thought of that.


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## peano (Feb 1, 2004)

A failing hard drive will cause the picture to pixellate randomly so in that regard it does affect PQ.


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## ZBoomer (Feb 21, 2008)

My hard drive failed in a previous 722 I had, and aside from not being able to perform DVR functions (pause, record, etc.) the picture quality was identical as before it failed. I have a Pioneer Kuro Plasma, so a "decent" display, obviously, and I leave my receiver on 1080i.

It never "pixelated randomly" or anything like that, the DVR functions just ceased to work, and I got a message the drive had failed.

I will say, once you are used to having a DVR, it's very difficult to go without it, lol.


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## bnborg (Jun 3, 2005)

ZBoomer said:


> My hard drive failed in a previous 722 I had, and aside from not being able to perform DVR functions (pause, record, etc.) the picture quality was identical as before it failed. I have a Pioneer Kuro Plasma, so a "decent" display, obviously, and I leave my receiver on 1080i.
> 
> It never "pixelated randomly" or anything like that, the DVR functions just ceased to work, and I got a message the drive had failed.
> 
> I will say, once you are used to having a DVR, it's very difficult to go without it, lol.


I certainly agree with your last statement.

Drives can fail abruptly, or more slowly. Failures not related to overheating would be more abrupt.


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## peano (Feb 1, 2004)

Yup. More slowly equals random pixelation. I've had both types of failures.


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