Tablo crashes and reboots when recordings fail

This seems to be a flaw in the firmware. When the box fails to record, due to low signal, Tablo will crash and reboot. Then, after the reboot, if you go into the recent recordings, you see the fresh error on top of the recordings list, indicating that a portion of a program could no be recorded due to low signal. I eliminated from my channels the weakest ones in the lineup scan list, leaving only the ones with all green bars. This minimized the crashes, but if there is rain fade in the area, and the recordings start to fail on the best channels, then Tablo will crash and reboot again.

Old news. Fix your OTA signal. Get a better antenna, get a bigger antenna, get a pre-amplifier, get a distribution amplifier, use RG6 coaxial cable instead of RG59, remove weak channels from your channel list, etc.

So many ways to improve your signal strength.

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I don’t see the connection between having no signal and the fact that the box is crashing. Even if I disconnect the RG-6 connector from the box, cutting out the signal completely, the box should not crash. When you disconnect a cable providing a digital feed to the QAM tuner of a TV, does the TV crash and reboot? No, it shows you either a dark screen or a blue screen. This seems like and idiotic answer. And yes, I do have an external antenna, going into a 5-port amplifier, that doesn’t overamplify, because the output ports have the same levels as the input port. By the way, you are talking to a veteran that worked at a cable company over 20 years, so I suggest that you be more careful in gaging your answers without knowing all the facts. Yes, I understand that the box will not crash when the signal is perfect. But, as I stated before, there should be absolutely no correlation between low signal and the fact that the box is crashing.

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I think that everyone on this forum would agree that rebooting the entire unit because one tuner receives a corrupted signal is a very poor design. But, since this has been a problem since the beginning of this product’s life, I’m assuming that it isn’t something that the programmers can fix with a firmware update.

I had hoped that when the quad came out, that a new product wouldn’t have the same problem, but I’m guessing that in order for all Tablo products to use the same firmware, they were required to keep the basic design the same. They made improvements to the WIFI, added a place for an internal harddrive and used a newer tuner design, but still the same reboot problem. So, it appears that all Tablo products will continue to suffer from the dreaded poor signal reboot syndrome. Maybe when they design the ATSC 3.0 model, they will be able to correct this obvious design flaw.

As @theuser86 stated, the best way to avoid this problem is to improve your signal strength, delete problem stations from your guide and just live with the fact that stuff happens and somethings are out of your control.

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Clearly this is a design flaw, because rebooting the system is a bit ridiculous. The one thing I could always count on TiVo was that no matter what else about it crashed, the tuners would continue to record.

As far as why it isn’t fixed in the firmware, that seems odd to me. Even if they couldn’t do anything for the old products, the firmware just runs code, and code has conditional checks that could certainly handle the error processing differently based on the newer products.

Nobody here will argue that a reboot for a signal issue is a good idea.

Maybe it will help to log a call to let support look at the logs. I installed my antenna in the attic, and ran RG6QS 15 or so years ago for mythtv then later added 2 HDHomerun’s, then upgraded to the ATSC version of HDHomeruns. to mythtv, then later still replaced Mythtv with TabloTV.

Suddenly after three years of operation my 4-tuner started to crash during recordings. Tablo support said I was over-driving the signal… I removed the preamp in the attic and the issue went away. So something external happened between my attic and the transmitters. So maybe tablo support can tell you if its a week or over-driven signal.

TVs will either go to a dark or blue screen when the signal is gone or when it is substandard for QAM processing. I believe this is a proactive approach. The TVs could show the tiling and freezing that goes on when the signal fails, but instead it switches to a full dark or blue screen, likely when the bit errors are high enough for the QAM to fail completely. Why? Well, because the manufacturer doesn’t want the customer to misinterpret that he may have a bad TV. So the dark or blue screen then becomes a universal “message“ for low or bad signal. It seems to me that Tablo takes a different approach. Instead of recording the tiling or freezing, and instead of recording the universal dark or blue screen; first, it hangs an entry on top of your recent recordings list, indicating that a portion of the program could not be recorded due to low signal. This succeeds and so far, so good. But then the box reboots and, after it comes back up, it tries to start recording the same program again, rebooting again and again, if the signal still fails. The big question is why does it reboot at all, at this precise moment, after each failure loop? I have to believe that a mandatory reboot is not part of the process. This would be ridiculous. It should hang the message, continue to monitor the bit errors, and when the signal stabilizes, restart the recording. They could put an option in the settings to ask how many times to reset the recordings before finally giving up on a program. If the user selects 3 failures, then the third message should say something like: “Your program has stopped recording after reaching the designated amount of signal failures.” After this point it should not do any other attempts and should dump the rest of the recording for that program. However, if the user doesn’t want to put a limit, then the box should continue attempting to record that specific program, until the program ends. This is why I consider this a firmware problem. What I am sure is that the box should never reboot due to low signal, or due to no signal at all.

This is beyond my technical knowledge or expertise but I’m sure Tablo would welcome you to work for them as a free full-time software engineer or developer to re-write the firmware to fix the problem. You’ll likely get a solution a lot quicker this way - maybe contact their recruiting manager.

Isn’t OTA VSB not QAM? …screen color is likely decided my manufacturer.

try this…

While we agree this may not be the most elegant solution, we believe it is the best choice we have available currently.

Any QAM signal over the air, or in a cable line, has the potential to be corrupted. In fact OTA signal has more potential to be corrupted than a cable signal, due to many factors not found in a closed system. The corruption in the signal should not corrupt the software that is orchestrating the process. Please be reminded that a customer could opt to plug their antenna directly in their TV tuner. But instead they have opted to purchase a Tablo for one reason, above all others, which is to record their OTA signal. I would think that 80% of your efforts should go in that direction. To ensure that the one thing the box is capable of doing, is done correctly. Thanks and I hope that my insights will help you provide a prompt resolution.

By the way, don’t want to be a pest, but I forgot to mention the most annoying part of this issue. On a two tuner Tablo, let’s say that you are watching a chanel with perfect signal, and the second tuner is recording one that has low signal. When the reboot happens, its hard to understand why, unless the customer is savvy enough and checks his recordings. This could lead to a great deal of frustration, because the last thing they want to see is a box rebooting, when everything “seemed“ to be working perfect. This could lead to misinterpretations and loss of confidence in your product. Thanks again!

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This excerpt is from a support issue two years ago:
Me:
My biggest concern is the behavior of the system when it encounters a weak signal. It seems like there is a bug or a design flaw that needs to be addressed to prevent a reboot in these cases. Is work being done to improve this behavior?
Tablo Support:
Yes, our engineers are working with the chip manufacture to improve this area.

Thus, Tablo is possibly stuck with the issue as much as we are since it appears to be hardware related or possibly chip firmware that Tablo has no control over.

That said, I agree with others who say to make the best of it by improving your signal quality and strength. That approach worked for me.

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You would think that a circuit board is fully tested before releasing a product. Is there a mention to what specific chipset they are talking about? Why would two years pass by with no resolution from a chipset manufacturer?

The digital processing should be simple enough. The QAM signal has the result of a mathematical formula inside each packet. The algorithm takes the basic payload data and does the same calculation, and compares the result to the same result that is carried in the packet. If they are different the system then tries to do Forward Error Correction. If everything fails then the system must decide weather to dump the packet or pass it along to the screen. If it passes on the data, garbage shows on the screen. Maybe it does an MER calculation and keeps passing the packets, so long as the MER doesn’t drop below 30. What I fail to understand is how the garbage in the signal is injecting garbage in a chipset, so much to affect its logical operation.

Again, searching the forum, 50+ results forweak signal reboot it’s unlikely you’ll find anyone in disagreement.

As noted in the first response “Old news”.
The topic dates back to at least 2015…

You imply there’s not an antenna connection to TVs. This is a misnomer. I’ve had my antenna connected to several TVs for decades, a tablo for about 1.5yrs after several years connected to a PC set up as an OTA DVR.

technical absurdity I suspect :neutral_face:

Yup, but I understand the need to vent, I do it often myself. But self-help is all you get for this situation.

Sadly, maybe a tablo isn’t the right device to meet your needs. Many do, some don’t… find what lets you be happy :slight_smile:

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My signal is good, but of course you have some channels with low signal. I eliminated those because of this problem. I got bad news for you. Even when you have excellent signal, this could also happen when you have rain fade and you are recording those fantastic channels with 5 green bars. I believe this is a great product that needs to be improved. But believe me, this is not new to me. I’ve lived with it for quite some time now. And with all the rain we are getting in Florida in the past few months, it’s become very annoying. No, I would think that it is a great product for me, or anyone, if they lived in the desert. The best signal doesn’t necessary fix the problem completely. That’s just a patch for a product that works well, but only under very specific conditions.

I previously had a TiVo. It was a four tuner. I had problems with weak signal, it was able to record with a few glitches. I would like to know why Tablo can’t? I have the best setup for signal reception available. The weak signal problems I have are from the transmitter. The field engineer has made some improvements. I receive five frequency’s and fifteen of my channels from one tower. My ABC is received by VHF antenna. NBC, Fox, and PBS are close enough I could probably get them with rabbit ears. My CBS comes from the translated tower. If any of those five frequency falters then I lose all twenty nine channels.
I’m not a tech guru, but if TiVo can do it then why can’t Tablo?

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Maybe they’re not explaining much further due to trade secrets :man_shrugging:

Very likely, different technologies. No TV I ever had does, nor a number of tuner cards in my PC have ever shut the entire thing down… must be specific to their unique and maybe copyrighted specifications, so no one will ever know.

In this case your OTA signal issues might be you are over driving the Tablo tuners. Read below about overdriving:

https://www.tablotv.com/blog/getting-technical-over-air-tv-reception/

When no recordings are taking place, and bad signal hits the tuner I am watching, the box acts correctly. It presents a dark image, with a circle spinning in the middle of the screen. Then later, it comes back up when the signal stabilizes again. Of course, if you are watching a live channel, it is also recording, in case you have to pause, rewind, or fast forward the live feed. No problems there. I believe the problem happens mostly when a scheduled recording event is happening simultaneously. When both tuners are recording. I wonder if it might be a multithreading problem with the hardrive recordings.