Wikipedia:Reference desk/Archives/Computing/2024 January 29

= January 29 =

Do cell towers have a scheduled downtime?
Every day at exactly 3:34pm my Internet access gets cut off for about a minute, so whenever I'm in an online meeting or am in a video game I lose connection. I live in a rural area without cable Internet access so I have to connect to the cellular network for the Internet, so I would assume this temporary outage is due to the cell towers rebooting or something. Is this a thing they do? —Panamitsu (talk) 02:43, 29 January 2024 (UTC)


 * This seems quite weird. If some sort of rebooting is needed in services like that, this is nearly always scheduled for the early hours of the morning when far fewer people will notice. It also seems quite surprising if more than one reboot is needed per day, or that otherwise one would be needed during the day time except in emergencies or physical maintenance. Indeed AFAIK it's fairly unlikely a reboot is needed for anything but updates etc and these generally won't be happening every day. Is this with multiple devices connecting independently or are all your devices connecting to a router/modem/access point/whatever you want to call it? If they are all connecting to some central device which I'll call a router for simplicity, is it possible that your device has a scheduled reboot for some odd reason? Nil Einne (talk) 10:19, 29 January 2024 (UTC)
 * Also if you don't have any schedules etc on the router, is the time consistent regardless of when the router was turned on? In other words, have you tried restarting this router say early in the morning or something, I mean even doing it at 1630 would be fine, and seeing if it affects when the internet dies? [//news.ycombinator.com/item?id=25802714]. Looking at that post and some other stuff, other things to consider whether it could be one of your devices doing something which causes the router crash or reboot. Or whether there could be some other device possibly owned by someone else doing something at this time causing issues probably somewhere else. (Unfortunately not much you can do about this, although you're in a rural area so possibly few neigbours, possibly not even easy for you to diagnose independently.) Nil Einne (talk) 10:19, 29 January 2024 (UTC)
 * Forgot to mention, at the very least, if you have access to the router, it's worth looking whether there's anything in the logs at the time. Nil Einne (talk) 10:21, 29 January 2024 (UTC)
 * Is mobile phone service also interrupted? --Lambiam 12:49, 29 January 2024 (UTC)

Repairing corrupted files, is it possible?
Hi guys!

I have come to the realisation that the 8TB secondary storage disk in my desktop PC is malfunctioning, causing it to become inaccessible when trying to read certain files or write to certain areas.

I've managed to copy nearly all of my data off of there, thankfully.

However, I have come across quite a number of .mp4 video files that cannot be played, some of them even unable to be copied. I found that one of the irreplaceable (valuable) videos on there is corrupt. I look at the file size and it's a few hundred megabytes like I expected, but the moment I try to play it with VLC or any media player pretty much, the player just hangs on loading for a while, then stops.

Is there any way to fix/repair corrupted video files like this, and make them playable again?

There's also a video game folder that cannot be opened with windows explorer at all. Every time I open it, a "The file or directory is corrupted and unreadable." error pops up. But if I look at this folder using TreeSizeFree Portable, I can see the contents of the folder! The contents all appear to be there as before.

P.s. I've tried running "chkdsk /f" on the disk that has problems (I'm on Windows 10 btw), and when I do that, it gets to step 2 then becomes stuck on a certain file's index (the same one every time I run it), freezes for a minute, then an "unspecified error" occurs, and the drive becomes inaccessible. If I try to open folders in that 'inaccessible state', I get an "A device which does not exist was specified." error, and it'll stay like this until I put the disk through an off on cycle - putting my PC to sleep and then waking it back up makes the disk become accessible and usable again, until I try to access those certain files or run chkdsk again after which the same exact issue repeats.

P.s. 2: I checked the status of the failing disk's SMART data using Crystaldiskinfo, and according to that utility, the drive has like >100 reported uncorrectable errors, 35 command timeouts, 192 reallocated sectors, and about 88 current pending & uncorrectable sector counts. I've been noticing the current pending & uncorrectable sector counts go up and sometimes go down with usage, which is weird to me (one day it might be 112, the next it's 64). — AP 499D25  (talk)  10:45, 29 January 2024 (UTC)


 * I'd take it to a data recovery specialist in your local area. If you've done the basics, then any further prodding without fully understanding the problem might just as easily result in more dataloss. For the future. If you have irreplaceable material, it is best to keep it on a system with a RAID 1 or better setup exactly for this reason. And if you really want to be safe, you should then have that sync to another location (like a family member), because a RAID mirror doesn't protect against a house burning down. —Th e DJ (talk • contribs) 12:31, 29 January 2024 (UTC)
 * A broken harddrive with no external cause is about the only thing RAID protects against, not against a house burning down, flooding, theft, a broken power supply blowing up the harddrives, ransomware, accidental file deletion, edits that turned out not such a good idea after all etc. That's why we need proper, versioned backups. The advantage of RAID compared to that is lack of downtime; not so important for most home users. PiusImpavidus (talk) 17:19, 29 January 2024 (UTC)
 * Honestly, I'm not gonna bother taking it to a data recovery specific for just one corrupted file. I've managed to recover about 98% of all my data that's on there. A lot of the files that are corrupted are stuff that I can replace, or stuff that I don't truly need. Out of all the files that can't be replaced, it's only just one video that's unplayable. That's all. It's an H.265 MP4 MOV video by the way, approx. one minute in length and 362MB in size. I was just looking for if there's a way to recover that corrupted video or get it back in playable shape at all.
 * further prodding without fully understanding the problem might just as easily result in more dataloss → you are right about this, the more I attempt to read certain unreadable files or locations on the disk, the worse the problems seem to get (freezing, becoming inaccessible). I've noticed that in the disk's SMART info according to Crystaldiskinfo, the "reallocated sector count" is no longer zero, and I think it's shot up as high as 198 or something. There are over 350 "reported uncorrectable errors" now.
 * For the record, this is a Seagate Barracuda 8TB 3.5" hard drive. It's actually still under its 2-year warranty (it's about 16 months old), so I'm gonna get it replaced under warranty.
 * Anyways, thanks for the advice! My next desktop will feature several backup hard drives, and I will probably use some backup software (such as Paragon) to make periodical, incremental backups of important data that's on my secondary storage disks. And then for the really valuable personal files of mine, I will probably save copies of them in cloud storage as well. — AP 499D25  (talk)  02:37, 30 January 2024 (UTC)


 * I came across this possible basic fix here:
 * Step 1: Download and install VLC Player on your system and launch the player and open the corrupted MOV file.
 * Step 2: Go to the Tools > Preferences > Input / Codecs tab in the Preferences window.
 * Step 3: Under Input / Codecs tab, select Repair damaged MOV files option. Then you can close the Preferences window and start playing the file.
 * There are further instructions about converting to eg .mp4 and other methods here: www.easeus.com/resource/mov-repair.html. NB This is a blacklisted site for WP. Always use a copy of the affected file when attempting a repair. If you are technically interested, the internal structure of .mov files is here: MinorProphet (talk) 20:24, 31 January 2024 (UTC)
 * I think you can use FFmpeg . It is a powerful command-line tool for multimedia processing. You can use it to attempt to repair the video file. Here's an example command:
 * ffmpeg -i input.mp4 -c copy output.mp4
 * Replace input.mp4 with the name of your corrupt file and output.mp4 with a desired output filename. Harvici  ( talk ) 03:12, 2 February 2024 (UTC)
 * Back in the day (say early 00s) I vaguely remember there used to be some application or tool (could have still been dos-based at the time, don't remember) that would allow you to read out sector by sector to omit anything that's damaged, cutting out any bad sectors from a file and trying to preserve the data. Whether the file would be usable after such an ordeal is another matter. No, can't remember the name, but it was definitely a dos thing, so most likely not viable any more. --Ouro (blah blah) 20:38, 2 February 2024 (UTC)
 * There's always  which will allow you to do exactly that.  Generally though it is better to make a block-by-block copy of the failing media and work on the copy, but for an 8 TB drive you'll need at least 12 TB as the target. Martin of Sheffield (talk) 21:23, 2 February 2024 (UTC)
 * Thanks for this note! --Ouro (blah blah) 05:45, 3 February 2024 (UTC)


 * First of all, I would like to say thanks everyone for your suggestions!
 * So I just tried out these tips today, and unfortunately, it seems the file is completely corrupt, like it is not a valid video file at all.
 * I tried out the VLC option, I had a look through the menus both in simple and advanced views, and I could not find any option or button called "Repair damaged MOV files".
 * If I open the file in QuickTime Player, a message saying "Couldn't open the file IMG_2039.MOV because it is not a file that QuickTime understands" pops up.
 * Just for the heck of it, I loaded the file into HandBrake, and what I got was a "no valid source or titles found" message. If I go to the activity log, it says stuff like "udfread ERROR: ECMA 167 Volume Recognition failed", "moov atom not found", "scan: unrecognized file type". HandBrake tries to scan the file in numerous different ways, e.g. mp4, mov, DVD, Blu-ray, but can't read it in any form.
 * I tried the ffmpeg command suggested by Harvici, and what I got was "Format mov,mp4,m4a,3gp,3g2,mj2 detected only with low score of 1, misdetection possible!", "moov atom not found" and "Invalid data found when processing input" outputs.
 * I can't do the sector read or block-by-block copy suggestions from Ouro and Martin of Sheffield anymore now, as I've already returned the old broken HDD for a warranty replacement new disk a few days ago. It's completely gone now.
 * So, it seems this file contains almost no machine-readable data at all, perhaps it's a blank file. I may inspect it using a hex editor one day (checking using the internal structure of mov files article provided by MinorProphet) to see if that is indeed the case.
 * Oh well, no biggie of a loss to me. I could easily climb back up that mountain (~30 min walk away from home) and take another video if I wanted to. I should probably consider myself lucky that out of the nearly thousand or so irreplaceable video files that were stored on that broken HDD, only this one 'IMG_2039.MOV' file had actually bitten the dust. — AP 499D25  (talk)  07:27, 9 February 2024 (UTC)
 * Just for fun I had a play around with the broken video file today. I downloaded a hex editor program (HxD to be exact), and observed the data construction of the file and compared it to other .mov files, as well as using the link provided by MinorProphet as a reference.
 * The file isn't actually blank (almost none of it is) as I initially thought, however there seems to be at least some rubbish data in the file for sure. The 'header' was totally corrupt and none of the bits making it up were like, ever correct.
 * Looking at my other working .mov files, the top header bits (ftyp qt) were the same as on the website, and so was the offset 20h (6D 64 61 74), as well as string 'moov' (6D 6F 6F 76) at near the end of the file. However my first block was different (00 00 00 14), offset 28h for me ended up being 68 1C 21 4E, and offset 2Ch appeared to be pseudo-random data across my files (some hex bits were the same, some different sometimes). FYI, these videos were all created with an iPhone SE 2nd gen, using 4K 60fps preset with HEVC codec. The videos were copied to the computer in their original HEVC-encoded form, rather than converted to AVC.
 * With that said, I tried editing in a header into the broken file, copying in the bits from the working files with the website as a reference. Unfortunately, this didn't get the file playable or recognisable again. Neither VLC or Handbrake could pick it up. Same ECMA 167 error in Handbrake.
 * On another note though, the file isn't entirely corrupt, and at least a good chunk of it seems to be valid data. If I go to the very end of the file, I am actually able to read valid footer information as well as metadata. I compared the footer and metadata to my working other files and I can definitely see the same pattern of data here, and same bits of data there. — AP 499D25  (talk)  12:35, 11 February 2024 (UTC)