# Searching for Signal on Cable In



## dobbie1 (Apr 15, 2002)

During the last couple of months I have been experiencing a loss of signal with some of my HD channels on my series 3. My HD channel lineup runs from 803 to 864. The channels I lose are in the 840, 850 and 860 range, but not every channel in tha range. All below that are ok, as well as all my none HD channels. In the last week I have had 3 sets of cable cards replaced, 2 sets of "S" and the last set is an "M". Comcast cable techs are at a loss, some think that the frequency is low for these channels and that is why I can't get them. Although, they can't explain why my Tivo HD unit that has only one "M" card gets all channels ok. The last tech that came out wants to try on other thing before he calls it quits. He seems to think it may be my Tivo unit going bad. Anyone got any ideas?

Thanks
Dale


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## mattack (Apr 9, 2001)

Do you have splitters? If so, try plugging the cable directly into the Tivo and see if you're getting the channels then. If so, the signal level is too low (at least that's my interpretation of the reason -- i.e. too low even to get a blocky signal).

I got cablecards since comcast's move of expanded basic channels to digital.. and I still can't get comedy central & MTV (and some other channels, but those are the ones I care about most) reliably unless I plug directly into the TivoHD. I have an amplifier on the way (our house has the maximum # of splits already, so it's not like I can get another outlet in my room), which hopefully will help it.

(this week I was manually switching from using the splitter to cable into the tivohd directly, to get daily show/colbert reruns at 1:30AM.. because the other talk shows are in reruns this week... then in the morning I'd plug the splitter back in)


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## dobbie1 (Apr 15, 2002)

No splitters and funny thing sometimes these channels will come in and sometimes not. And it isn't all the channels in the 840 to 864 range, just some of them. Thanks for the response.


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## bkdtv (Jan 9, 2003)

The inability to tune channels on Comcast is almost always related to one of two things:


 *You are not authorized to receive the channels.*

There are three possibilities:

You aren't supposed to be getting those channels with your package (even though you *think* you are), so you will not receive those channels on any box;

 Someone at Comcast messed up and did not authorize your account for all the channels you wanted, so you will not receive those channels on any box; or

 Your CableCard is not activated / authorized correctly, so you will not receive those channels on the specific box (or tuner) that uses that CableCard.

 *Your signal is too "hot" (strong) for the TiVo to tune.*

This will cause the TiVo to intermittently fail to tune a particular channel. This rarely occurs on Comcast unless the user has some sort of amplifier (such as a splitter with a powered amp) installed.

If the Messages & Settings -> System Information -> *DVR Diagnostics* screen reports most channels with a signal under 95, then you can rule this out. If most channels do report a signal in the 99-100 range, then you should be able to eliminate this problem by screwing a 3dB or 6dB attenuator onto the end of the coax. If you have a splitter lying around, you can install that before the TiVo and it will serve the same purpose (i.e. reducing the signal by 3-4dB).

 *Comcast made changes to their system and forgot to update their CableCard channel maps. *

Cable companies use separate channel maps for their (a) their own boxes and (b) all third-party CableCard devices. Sometimes after maintenance, typically to make room for new channels, Comcast will update their channel maps for their own boxes but forget to do the same for CableCard boxes. As a result, no one with a third-party CableCard device such as a TiVo, Moxi, or TV can ever tune those channels.

To fix this, Comcast needs to update the CableCard channel maps at the headend. To troubleshoot this problem with Comcast, you need to make it clear that the channel works with the cable company box but cannot be tuned by any CableCard device. Mention that the channels maps are wrong and request the next tier of customer support. If you can't get the Comcast rep to listen to you, then have the Comcast installer (that they send out to your home) make the same request.

You can probably rule out problems #1 and #3 because your TivoHD always receives these channels and you say that the channels tune intermittently on the original TiVo Series3. I would guess that #2 is the cause. If you have a splitter lying around, install that before the TiVo to reduce your signal strength. If you don't have a splitter lying around, then you can order one 3dB and one 6dB attenuator right here.


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## dobbie1 (Apr 15, 2002)

The TIVO HD unit downstairs get everything, ok, so, hopefully the cable cards are not authorized properly in the series 3 unit. I just hope the series 3 unit doesn't have something going out on it. Hate to lose a lifetime sub after only 3 years.


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## bkdtv (Jan 9, 2003)

dobbie1 said:


> The TIVO HD unit downstairs get everything, ok, so, hopefully the cable cards are not authorized properly in the series 3 unit. I just hope the series 3 unit doesn't have something going out on it. Hate to lose a lifetime sub after only 3 years.


Note you always need two CableCards in the original TiVo Series3, regardless of card type. It cannot support both tuners with a single card like the newer TivoHD.

If a channel tunes intermittently, that could be because one CableCard (and thus one tuner) is authorized while the other CableCard (and thus other tuner) is not. To check that, you can swap tuners by pressing the liveTV button. If swapping tuners allows you to tune that channel, then you know for certain that one card is not properly activated / authorized.


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## dobbie1 (Apr 15, 2002)

Thanks for the reply. I have 2 "M" cards installed. It does appear that cable card "2" is not completely activated. The status on one screen reflects authorized, however, another screen reflects "not staged." Cable card "1" reflects "authorized" and "ready." I'm not sure that my problem will completely be solved with getting cable card 2 setup properly. Before we started swapping out cable cards, the original ones had worked perfectly for almost 3 years. Only recently have I started having problems with some of the HD channels, and only ones in the higher number range 840 - 864 and not all of those.


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## Lrscpa (Apr 20, 2003)

I too have been having this issue occasionally with certain HD channels. I have a Cablevision supplied Tuning Adapter, which I have amplified (CV supplied amp), and then split between the Tivo and the TA. Reason this was done was because of a low signal (-8dBmV t0 -11dBmV on the TA, 40's and 50's on the TiVo). Now the signal on the TA runs from -3dBmV to +1dBmv, and channels are generally in the 80-100 range. PQ is generally excellent

Interestingly enough, when I do get pixellation or "Searching for signal..", I check that channel on the DVR diagnostics. The signal will bounce from 0 to a max of 50, which the channel on the other tuner will be in the 90-100 range. 

So in these cases, I don't think the problem is due to a hot signal.


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## mattack (Apr 9, 2001)

bkdtv said:


> *You are not authorized to receive the channels.*





I've been curious about this. Does the Tivo discriminate between channels it can't tune and channels you aren't authorized for?

It seems like *most* of the time I just get a blank screen (no 'searching for signal...').. but sometimes (I think on some channels, I haven't narrowed it down), a comparatively TINY little Tivo 'popup' comes up that says something I don't remember. It isn't as blatant as 'not authorized', but it is a little window (no OK button or anything) that has a Tivo icon in it.

Yes, that's vague... But since I have signal issues (too weak a signal due to my necessary splitting), it's sometimes hard to tell which channels I should be getting and am not.


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## dobbie1 (Apr 15, 2002)

Well the cable guys came out yesterday and determined part of the problem was signal strength was to strong, put a splitter on the drop amp. This seem to help bring in some of the HD channels that were not coming in before on the series 3. However, in putting the splitter on the drop amp it messed up my cable modem signal. I removed the splitter and connected it between the series 3 and the wall outlet which provided the same result, but did not affect the cable modem signal. I'm still sitting with cable card "2" not completely activated, status is "not staged" even though it is authorized. The Comcast techs now say they have done everything they can and the problem must be in my TIVO. Guess I will have to live with what I have.


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## drcos (Jul 20, 2001)

1. Channel map issues:
a. Check your DVR diagnostics screen when trying to tune to a channel that doesn't come in. If it says 'Failed. Wrong card state' for status, it's a channel map issue from the cable company.
b. You can also verify this by going to Cable signal strength. Scrolling up and down through the channels will indicate which channels are not mapped (they will not show up).
I have found that (typically) removing the cards and then reinserting them followed by a restart will force the cards to reload the channel maps from the headend.

2. Not authorized: If you have a good signal, and the diagnostics indicate 'tuned' (the signal strength screen would show good signal but no picture), you are probably not authorized to receive the channel. If you are paying for the channel, you need your cable company to fix the settings in their computer (a truck roll is NOT needed).

If you don't think it's worth all the hassle, go down to your cable company and play with their DVR for a couple minutes. Then go home


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## dobbie1 (Apr 15, 2002)

Thanks drcos, will give your suggestions a try.


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## Das Achteck (Mar 9, 2005)

bkdtv said:


> The inability to tune channels on Comcast is almost always related to one of two things:
> 
> 
> *You are not authorized to receive the channels.*
> ...


I am having a problem with Comcast that does not seem to related to any of those things. I have an SA M card in a TiVo HD and another SA M card in my TV. Out of the blue three channels started producing a black screen and no audio when tuned by the TiVo, but are OK when tuned by the TV through the CC in it. On rare occasions a channel might exhibit a very blocky or frozen video, or have audio if left tuned for a while.

TiVo diagnostics show all three on the same frequency. All are SD digital and one is even in the unencrypted basic level. Signal strength is 100, there is signal lock and program lock, SNR is 38 and there are no RS errors.

I have spent time with three techs at TiVo. We have run all the diagnostics: Status is Locked, the CC is activated, the CC is paired and the three channels are Ent (authorized). I have carried out all their suggestions, as well as some I dreamed up. These include repeating Guided Setup, warm boot, cold boot, add 6 db attenuation, swap the coax cables between the TV and the TiVo. The TV continues to show all three channels while they remain black when tuned through the TiVo.

I am thinking of picking up another CC and going through the activation thing from the start. I just can't see that contacting Comcast will get me anywhere. As soon as the see the TV working OK they will say it is TiVo's fault. And it may be, they have suggested a swap. I'll wait for the new d update before deciding.


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## dronca (Sep 21, 2008)

I am having a similar issue with mine. At random times the TiVo is unable to tune in particular channels, with the message "Searching for Signal on Cable In." I've had the cable card checked and Comcast said it was fine. They swapped it anyway.

The weird thing is (weird to me, anyway) is that when it loses signal, it's only for network channels in HD (i.e. ABC, CBS, NBC, CW, FOX). I can go to HBOHD or USAHD or whatever just fine. I can also go to the non-HD network channels just fine.

This doesn't happen all the time, and when it does it can last 30 seconds or 4 hours. I'm losing recordings now, it's driving me nuts.

Will try the splitter thing mentioned in post #4 (checked the signal and it came in at 100), but I was wondering if anyone else had further insight.


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## mattack (Apr 9, 2001)

dronca said:


> The weird thing is (weird to me, anyway) is that when it loses signal, it's only for network channels in HD (i.e. ABC, CBS, NBC, CW, FOX). I can go to HBOHD or USAHD or whatever just fine. I can also go to the non-HD network channels just fine.


That's not really weird IMHO, because it is likely due to signal quality issues only in specific bands... "HBOHD or USAHD or whatever" is in a different signal range, and you're apparently getting those just fine.


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## Pvgibbs (Jul 5, 2005)

Having the same issue with Comcast in SE King County (Seattle). For about 2 years I got the following channels with no issue on my TivoHD: 

110-HD Local Channel 
TNT-HD
ESPN-HD

But as of a month ago - these channels show the "searching for..." message with a grey screen. Other HD channels worked just fine. 

Oddly these all came "back" fine last week, but this week only 110-HD is working -- TNT-HD and ESPN-HD are once again showing the "searching for.." message.


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## Doug G (Mar 3, 2005)

Just had a similar problem with my Vz FIOS service. Two HDs, M card in each, one stopped receiving some channels (USA HD, TWC HD, etc.) and some channels had really low receive signals (fluctuate between 40-60&#37 would pixelate badly while other channels were at/near 100%. But other HD unit was fine and showed no problems. Rebooted several times, no joy. Re-ran guided setup and at same time rebooted my NIM100 at that unit figuring maybe it was corrupting some channels and after these two things its all back to normal. I have no idea if I really fixed it or not. Had been running trouble free almost 6 months and no changes so I was confident it wasn't a physical problem.

During this I tried to run DVR diagnostics and it hung so I had to power cycle. Oddly my other unit (the one without ch problems) did the same thing! I had noticed several days earlier that many of my favorite channels were missing (like about 1/3 of them) and this had happened on both units. I figure it must have been something Vz did. I guess this might have gotten both Tivos in some bad state, but whether that had anything to do with the inability to tune certain channels on the one isn't clear.

So if you have this problem try repeating guided setup and if you have a NIM100 or other broadband coax device on the same segment, reboot it too. Worked for me!


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## dturock (Feb 16, 2010)

I've got a lot of experience with this problem. And after yesterday I have even more information to confirm what the problem is, so I thought I'd post what I've learned here to hopefully help others that have been as frustrated as I've been.

My config is a Tivo S3 with two "S" cards and a Tivo HD with one "M" card and I'm on Comcast.

Somewhere about 3-4 months ago I started getting the "Searching for Signal..." error. It was only on the HD network channels (CBS, ABC, etc). All of my other channels (TNT, etc.) and even HBO were all fine -- never a problem with any of them. But for about 2 weeks back then we'd just lose all of the network channels (which is of course where we Tivo the most shows...).

On one of my calls to Comcast Support back then I got a guy that seemed to understand the problem. He basically said: it is not your cable cards. We (Comcast) have an equipment failure on the head end and they're trying to fix it. He assured me that they're getting a lot of the very same complaints and they want to get things fixed as soon as possible. And the reason it's just the HD network channels is because the hardware that is failing is specifically to broadcast those channels.

Sure enough after a few more days life went back to normal and things were fine -- until just recently on 2/4/2010. That evening things went out at 8PM and stayed out until just about 11PM. And then every day since then things go out during the day, in the evening, etc.

So I called this past Friday night hoping to find another person like that last guy that would acknowledge that the problem is on the Comcast side. But they weren't aware of a problem and wanted to send someone to my house. 

So a service person came yesterday afternoon and the gentleman was very helpful. He said that he didn't know for sure what the problem was but was pretty sure it was a problem on the Comcast side. He said the previous day he had a number of service calls, all of them for Cable Card problems. He had even swapped out one guy's cable cards but it had no effect on the problem.

He said that all he can do is pass all of the problems up to his supervisor, who then sends the complaints to whatever department runs the head end.

He also said that the reason that, when I call cust support to say "is there an outage?", they don't know about it because they only know about line outages. They don't talk to the people at the head end, so they wouldn't know if there was an outage there or not.

And the reason that things go down in the evening and stay down for a while is because there is no one at the site -- so when the equipment dies, someone needs to drive in to reboot it.

Update: the channels have been working fine now since Sunday so hopefully things are fixed now.

Hope all of this helps anyone else hitting the same problems,

Drew


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## cjv2 (Dec 16, 2009)

dturock: Might be worth sending an email to [email protected] about your situation.

Short version of my story is: My headend recently converted to the World of More lineup. When this was implemented, there was one channel that was constantly showing "Not Authorized" on my Comcast DVR, and would not tune on the Tivo. By way of the AVS Forum, I chatted with others on my headend who reported the same issue.

Comcast over the phone listened to a point, finally saying that it must have been a "network issue." Of course, they offered no resolution other than that they would work on it somehow and maybe one day something would change.

A week later I emailed the address above (I wanted to give them time to get it right). I made sure I was detailed about what was going on and what I had learned about the scope of the issue in the locality. Whoever it got routed to called me the next morning to advise me they were looking into it. By midday it was corrected. She even knew root cause, which was that someone had typoed a 2-character code somewhere in configuring the headend.

My read: If you have a true Comcast-side problem, the email path is probably the most reliable way to get to someone who actually knows something besides "it must be at the customer end" speeches.

Hope this helps.


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