# Bolt pixelation (TWC)



## rcoates777 (Jun 29, 2005)

Gang -

[Apologies in advance but this is probably going to be long]

I've had the Bolt for 2.5 years now & things have been good. I am on the TWC legacy plan from Spectrum. Quite a while ago I decided to try taking my Tuning Adapter (TA) out of the equation as apparently none of my channels require Switched Digital Video. That helped. Recently I've started to have some pixelation problems. It is pretty bad on my channels from 1200 and higher. From channel 405 and below it's not too bad.

The Spectrum tech was out and, of course, pronounced that their signal was fine and that the problem was with my TiVo. He actually fired up his own set top box and things looked good. But despite his persuasive demo I'm not convinced that it isn't a signal problem. (My thinking is that perhaps the tuner in his STB has different tolerances than those in the Bolt.)

Here are some #'s from the TiVo Diagnostics screen. If I've missed some important ones I will be glad to supply them. Most all the 4 tuners show a signal strength of 67% and SNR of 27dB. Chnl 405 (one of the good ones) sometimes goes to 70% and SNR of 28dB. They change at the same time. So the good channels and the heavily pixelated ones have very similar #'s for strength and SNR. One difference is that the RS Uncorrected counts are much lower on the 'good' channels. Like about 3/minute. The bad ones RS Uncorrected increase steadily. In a 1 minute test there were 319 Uncorrected errors on chnl 1209. I've never seen the RS Corrected be other than 0.

I tried putting the TA back into the equation. It got the channel list OK but I never saw any picture on the screen and the Bolt Diagnostics indicated nothing was being received. I think it would simplify things not to do much with the TA at this point. I removed it so the cable-in is going directly into to the Bolt.

About 3 months ago Spectrum replaced the box where everything enters the house. They replaced splitters, etc. That tech was a supervisor and very good. Inside the house he replaced some passive splitters with a single 0 gain active splitter. The problems did NOT start at that time but only recently.

Anything else I can supply? It's tough getting these things fixed as the techs just want you to move to Spectrum boxes and want nothing to do with TiVo or CableCards.

Thanks in advance!

Bob - Pinehurst, NC


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## JoeKustra (Dec 7, 2012)

Two items. RS Corrected doesn't work on a Bolt or basic Roamio. Your signals are too low. That gives you two choices. Call Spectrum and hope they agree. Other choice, add an amplifier. I have an old Radio Shack active splitter (8dB gain) on my feed since I split the signal 4 ways at two locations (after the cable feed splits it twice). My signal is 90% and SNR is 36db on about 200 channels going up to 860MHz. The lowest channel is 123MHz. My cable modem has a signal of about 2dBmV and a SNR of 40dB on 24 channels. It gets a few errors every month. I never get errors on three different Roamio boxes. The magic for me is replacing the tap at the pole every year. If I don't get that done my system goes south. I have a very nice cable company.

It might help if you can make a graph of the signal level/errors vs frequency for some channels. That might impress the service guy. You should never see those errors increase on the TiVo while watching.

To see something weird, unscrew the rf coax while watching the Diagnostics. You may pass one million errors before you screw it back on. Your problem is not related to cable cards.


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## rcoates777 (Jun 29, 2005)

Thanks, Joe! I will try to absorb this. How do I respond to Spectrum when they say "it looks OK on your TV when we substitute our STB for your TiVo?" I wasn't savvy enough to ask the tech for what sort of #'s he was seeing. Not sure he knew much about #'s - he just saw a little green light on his meter and said the signal was fine.

I have posted something on our community message board to see if someone else nearby has a Bolt so that I can look at their Diagnostics and see what sort of % and SNR they are getting. What is a good target for signal strength % and SNR? It ran great for years.

I was thinking that the signal was too weak to drive the TA but that is just a guess.

I'll keep plugging but I fear this is going to be a long haul! I may have to rent a Spectrum STB short term while I work on getting the TiVo running again.


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## JoeKustra (Dec 7, 2012)

Ok, let's assume the tech is an idiot. The "perfect" numbers do not exist. On a Roamio and Bolt, the AGC circuit tries to make the signal 90%. If the SNR is 36db, you have a winner. I have a Sony TV, and two clear QAM channels. When I use its diagnostics, the signal is 70% and the SNR is 36db. Most televisions do not have diagnostics.

I hate to say it, but your Bolt is 2.5 years old. I would not rule out it being defective. A test, which I use, is to select any channel and then restart the box. When it comes back, check the diagnostics since all tuners should have the exact same numbers. But even so, the Bolt may be sick. I don't know if you are running TE4, but if you call TiVo they will probably replace it with a Bolt running TE4 (and you will lose all recordings). If both Bolts are active, you can use TiVo Online to move your programs. There is a 50% chance the transferred programs will not play is you are using TE4. I'm sorry, but I don't have Spectrum or a Bolt. One sign of a sick Bolt is a ODT (System Info) well over 50C.

I have three active basic Roamio boxes (one TE4), 2 spare Roamio and a Premiere that is powered off except on weekends. All active Roamio boxes have 3TB drives.

Sample:


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## Slumpert (Oct 18, 2019)

Just tossing this out there, are you sure your bolts’ fan is still spinning? Pretty easily to just pop the 1/4 top section off and observe it.


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## rcoates777 (Jun 29, 2005)

Slumpert said:


> Just tossing this out there, are you sure your bolts' fan is still spinning? Pretty easily to just pop the 1/4 top section off and observe it.


I'll give that a try. My ODT says 62*. I think that's pretty close to what it's always been. I appreciate the tip.


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## JoeKustra (Dec 7, 2012)

rcoates777 said:


> I'll give that a try. My ODT says 62*. I think that's pretty close to what it's always been. I appreciate the tip.


There are several threads on ODT. Just as a test I would find a fan (any fan) and have it blow on the Bolt. Check the condition and ODT after an hour. I give it a 10% chance of fixing your problem, but after three years that internal fan may have some dirty blades. Some members leave the cable card cover off also.


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## rcoates777 (Jun 29, 2005)

Joe - something easy to try - I like those. I took my CableCard cover off close to Day 1.
Today I am planning to run the coax directly to the Bolt instead of going through the active zero gain splitter just to eliminate that one variable.

I found a good TiVo support article on signal strength and SNR. Basically for the Bolt they can tolerate 50% signal strength but they suggest 80-99%. (I'm at 67%).

For SNR the acceptable range is 29dB - 35dB. (I'm at 27 dB). An amplified splitter would not improve SNR, right? Before throwing in the towel I'd like to get that SNR into an acceptable range.

I also checked what Spectrum charges for DVR rentals. The hardware wasn't too bad - like $12/mo. but then they tack on the 'service' which could be close to $20. Ouch!

The article about signal strength & SNR is at: Tivo Customer Support Community

Stay tuned!


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## JoeKustra (Dec 7, 2012)

re: link
We both know RS Corrected is always zero on our boxes. It only works on older boxes or boxes with 6 tuners. I have channels with 37dB SNR without any issues. They go to 37dB at the same time my signal % jumps to 92. Also, I see the same behavior with some channels that jump to 35dB and 87%. My numbers for channels as well as my modem are consistent 24/7. I'm lucky to have a very smart TiVo owner on the same headend. When something happens there is a DSLReports thread for my cable company.

One day last year during a snow storm I made an Excel spreadsheet of every channel and its Frequency, QAM channel, Call Letters/Network, and Sub-channel. All 390 (at that time). I now have over 400 since there are place holders over 1000 for UHD channels I don't get yet and are dead frequencies.

May I ask the model number of your modem?


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## rcoates777 (Jun 29, 2005)

My cable modem is an Arris SB6121. From its diagnostics is see Downstream SNR of 37-38dB with power of 0 dBmV. I know very little about cable modems. What effect would it have on the TiVo as the cable signal does not pass through it. My understanding is that the modem only interacts with TiVo for service connections and streaming.

Does the fact that the modem shows a downstream SNR of 37dB -38dB and the TiVo only 27 dB mean anything or are they 2 distinct signals that are unrelated?


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## JoeKustra (Dec 7, 2012)

rcoates777 said:


> My cable modem is an Arris SB6121. From its diagnostics is see Downstream SNR of 37-38dB with power of 0 dBmV. I know very little about cable modems. What effect would it have on the TiVo as the cable signal does not pass through it. My understanding is that the modem only interacts with TiVo for service connections and streaming.
> Does the fact that the modem shows a downstream SNR of 37dB -38dB and the TiVo only 27 dB mean anything or are they 2 distinct signals that are unrelated?


The modem numbers are average. That's an old modem, but it may still have a spectrum analyzer.

I'm only curious if it also had low numbers. Well, if you have Chrome or Edge, enter 192.158.100.1:8080 in the address bar. Name is admin, password is password. Let me know if that works. BTW, did you try the tuner comparison?

My cable:







Those are the real numbers. They get to 90 with AGC. Also: Charter Spectrum forum | DSLReports, ISP Information you might want to see if others are having problems.


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## rcoates777 (Jun 29, 2005)

JoeKustra said:


> The modem numbers are average. That's an old modem, but it may still have a spectrum analyzer.
> 
> I'm only curious if it also had low numbers. Well, if you have Chrome or Edge, enter 192.158.100.1:8080 in the address bar. Name is admin, password is password. Let me know if that works. BTW, did you try the tuner comparison?
> 
> ...


JoeK -

Was the URL supposed to be 192.*168*.100.1:8080 (not 158) ? The modem #'s I sent earlier I got from 192.168.100.1 (without the 8080). When I try 8080 I get 'connection refused'.

Things have gone from BAD TO WORSE this morning. I connected the wall output directly to the TiVo (bypassing any splitters). The results were about the same with respect to signal strength & SNR - maybe just a little less (26dB vs. 27 dB) - so perhaps my 'no gain' splitter amp is providing a little gain. BUT when I reconnected things to the original state (Wall->Splitter->Tivo) things went way down hill. Now I get virtually no channels. Signal strength is 0, SNR bounces from 9 to 16 to 27 continually. I went back to the direct from wall config and same problem. I suppose the wall coax could have failed while I was swapping things around but my Internet is fine (just did speed test) and phone (VoIP) is working and they are using same coax from wall.

I powered down TiVo and let it rest for a while - no change. I think I'm screwed. My current thinking has shifted from bad signal to bad TiVo. At least I can still use it as a streaming device. I hate the idea of buying another LifeTime service (AIP). And while I love TiVo what's the deal with a 90 day warranty?

Maybe this will force me to cut the cord ......


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## JoeKustra (Dec 7, 2012)

Yes, it was a typo. The modem may be too old to have the spectrum analyzer. The modem still works. Then as a test, connect the modem coax to the TiVo. It won't hurt anything but you will get evil messages on the TiVo and all you are testing are the channels. My cable drop goes to a 1 to 2 splitter. One leg goes to my modem, The other leg goes to a 1 to 3 splitter which feeds three locations in my house. Two of those locations have an active amplifier/splitter with four outputs each.

You have a bad cable/connector or a bad TiVo. This should be your final test. I suggest a SB6183 modem. Use Google for prices.


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## rcoates777 (Jun 29, 2005)

Still battling my pixelation - but in the meantime here's another question. How can SNR be too high? I'd think the less noise the better. I can understand signal strength being too high. I wonder if TiVo really measures them both even though the diagnostics reports both. I say that because when one changes the other changes at the same instant.

I have appointment at another TiVo owner's house in 2 days. I'll check his signal levels and perhaps I can plug my unit in there and see how it looks.


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## JoeKustra (Dec 7, 2012)

rcoates777 said:


> Still battling my pixelation - but in the meantime here's another question. How can SNR be too high? I'd think the less noise the better. I can understand signal strength being too high. I wonder if TiVo really measures them both even though the diagnostics reports both. I say that because when one changes the other changes at the same instant.
> I have appointment at another TiVo owner's house in 2 days. I'll check his signal levels and perhaps I can plug my unit in there and see how it looks.


I think you answered your own question. The way TiVo does its thing, as the signal rises, the SNR rises. It's logical, not a bug, like no RS Corrected. I wonder if the EDGE has the same problem? I have a Premiere that uses the same cable except for the last three feet. As I posted, my Roamio is almost always 90/36. The Premiere is around 76/36. My TV (also on same feed except last three feet) is 70/36. I have a Roamio OTA also connected. Also 90/36 on the two un-encrypted channels but it doesn't have a cable card and it runs TE4. Simplified, as the signal goes higher, and the noise doesn't, the SNR should rise.

Show me a schematic and source code and I can give you a better answer. There's no reason to be afraid of connecting your TiVo to your friends cable. Before disconnecting the other TiVo, check the VCT number. That number identifies your headend. If the number is the same, the channels should be the same.

I guess it's easier to take your TiVo for a ride than using the cable feeding your modem? Speaking of modems, my modems signal varies from 0dBmV to 4dBmV but the SNR is from 40dB to 40.2dB. Today the status show 3.1 to 3.9dBmV and SNR is 41.1 to 41.3 dB across 24 channels.

Also see: Signal-to-noise ratio - Wikipedia


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## rcoates777 (Jun 29, 2005)

I took my Bolt (with severe pixelation) to a TiVo neighbor's house for some testing. The results were somewhat inconclusive but certainly pointed to a bad unit. On his coax in one place in house I got pixelation (there had only been a DTA in that room - not a TiVo). But in 2 other rooms with TiVo I got no picture and signal strength & SNR stats from diagnostic page were much lower than his and jumping around a lot - just like at my house.

FF. TiVo sent me a 'renewed' Bolt which arrived yesterday. It worked just fine. I even managed to get back to the classic UI (with the help of some forum research).

My next task is to try to get some shows off my old Bolt onto my new one.

I could not be more pleased with how TiVo treated me with all this. It may have helped that I've been a user for close to 15 years.

Thanks to TiVo Community for your help with this. It's great to have my TiVo back online again!

Bob


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## JoeKustra (Dec 7, 2012)

I have no problems using TiVo Online to move programs from TE4 to TE3. I only move about 10 at a time.


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