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blu87

join:2004-03-23
united state

Signal problem again, I think

Could someone please tell me what an acceptable range is for the Current FDC, RDC, and QAM 256? And whether there's anyway I can be sure the problem I'm having is a signal problem?

The problem I'm having is that TV "3" is not getting a picture and shows, "One Moment Please. This channel should be available shortly." It's similar to a problem I was having in July and that problem was caused by the amplifier getting "killed" by a storm and a tech had to replace it.

In July, I had tiling on TV "2" but this time the picture is fine, but the signal levels are worse than usual, but not as bad as in July. On TV "3", I tried rebooting the box (SA Explorer 2200, yes I know it's outdated), but that didn't help. I decided to try again a little later, and now the box is stuck in a loop - it just keeps rebooting. It very briefly displayed "tr.09" and "-nu-." Under DAVIC, it shows, "slow-boot wait." The signal levels for TV "3" are almost exactly the same as in July, when the amplifier was dead.

Any thoughts on this? It really p***es me off because I have tons of stuff to do for the holidays and now I have to wait around for Comcast to come at a scheduled time that I'm sure they will fail to show up for.

Here's what the values are for TV "3":

QAM-256
Level: -20 dBmV
S/N: 0 dB

RDC
Power: 47 dBmV

FDC
Level: -32 dBmV
S/N: 19 dB

Here's what the values are for TV "2":
QAM-256
Level: -13 dBmV (-11 dBmV is normal)
S/N: 33 dB (37 dB is normal)

RDC
Power: 53 dBmV

FDC
Level: -24 dBmV (either -14 or 14 is normal)
S/N: 26 dB (24 dB is normal)

nrobot80

join:2012-12-05
Union City, GA
If you need an amplifier then your bad signals are being amplified along with your good signals. The "one moment please " is the digital version of snow or a fuzzy picture which you would get if the signal would be if it were analog. The only solution would be to have a tech come out check the lines AND the amp. If you only have 3 TVs connected then you shouldn't need an amp unless your outlets are far from the splitters. When the tech does come make sure that they check the lines from the tap to each TV. Your other TV the tiling problem is also a result of low signal or bad lines. When you call don't let the phone rep talk you I to swapping out the box, that may be part of the problem but not the whole solution to the problem.

blu87

join:2004-03-23
united state
Thanks. We only have three TVs connected to cable, but it was originally set up for four, we just don't use the fourth outlet. If I recall correctly, the amp was originally installed between 2004-2006, when we only had analog cable. I remember the signal on TV "3" being so bad that one channel picked up a local FM or AM radio station. An outside line was replaced and something was done at the tap, but they ended up installing the amp too. Each of the four TVs go through two splitters, there are a total of three splitters.

I know the cabling for the two upstairs TVs needs replacing rather badly. One line is on the roof and it's spent the last 22 years getting baked in the sun. So... if the coax cabling for the downstairs TV is ok, but the amp is still needed, doesn't that mean the problem is outside somewhere? I've spent the last 15 years or so dealing with these signal problems, I'm really getting sick and tired of it. At least with analog, I still got a picture. Screw digital, it sucks!

But what about the numbers I provided? Does that tell you anything? Or do I need to post more info?


telcodad
Premium
join:2011-09-16
Lincroft, NJ
kudos:15

1 edit
said by blu87:

But what about the numbers I provided? Does that tell you anything? Or do I need to post more info?

One other thing that would be good to know is what the frequency is for that QAM-256 video carrier, compared to other channels that are coming in OK

If you use a cable modem, it would also be good to see what the channel frequencies and levels are for that.

Old, weathered coax cable and splitters that may have managed to work OK for analog TV, can be a problem for digital TV and other services, since the analog channels were typically located at lower frequencies/channels received by older "cable-ready" TVs, while many of the new, added-on digital carriers were placed at higher frequencies.

Just replacing any older, low-quality splitters that you may have installed yourself with newer, higher quality ones (see: »[Connectivity] Recommended splitter) may resolve your problems.

Also take a look at these two recent threads, from other posters who were also having video issues, for some additional info/ideas:
»Poor picture quality
» Do I need to get an amplifer and active return?

EDIT: Given your latest post, I realized that I originally misunderstood what you meant by TV "2" and "3" (not channels, but sets). Modified my post based on that.

Cable Employ

join:2012-07-23
Saint Paul, MN
reply to blu87
If those levels you are posting are the levels that a particular channel is seeing, you have a major signal issue. Ideally, you would be reading between -5 and +5dBmv at the TV.

If you have cables laying on your roof that have not been touched for the past 22 years, that could be a problem. Do you have any splitters on the roof? The easy would be to replace any splitter's that you may have on the roof to begin with. Otherwise, set up a service call.

blu87

join:2004-03-23
united state
reply to blu87
Thanks for the help, I've been trying to educate myself on these issues, but it's been hard finding websites that explain this sort of stuff.

Here's an update: I called Comcast Thursday morning and after 42 minutes and talking to four different people (one was totally dumbfounded), they finally determined that a tech needed to come out and check the box. I explained that I believed it was a signal issue, but they insist it's a problem with the box. An appointment has been set for a tech to come out.

Thursday night, I came home to find that the STB has stopped rebooting itself and was turned to channel 5. However, there was no picture and the message, "One Moment Please. This channel should be available shortly" was displayed. I turned the box off, I may have rebooted it and shortly thereafter, I finally got a picture on some channels. I checked the RF Statistics page and came across something that may be interesting which I have posted below.

TV "3":
Channel 110 - Science Channel (QAM Frequency 525.000 MHz)

QAM-256
Level: -19 dBmV
S/N: 0 dB when status is locked and 27 dB when status is unlocked

RDC
Power: 47 dBmV

FDC
Level: -23 dBmV (was -32 Wednesday)
S/N: 23 dB


TV "2":
Channel 110 (QAM Frequency 525.000 MHz)

QAM-256
Level: -10 dBmV
S/N: 35 dB

RDC
Power: 55 dBmV

FDC
Level: -16 dBmV
S/N: 22 dB


For the heck of it, here are the numbers from TV "1" on Thursday morning:

QAM-256
Level: -17 dBmV
S/N: 30 dB

RDC
Power: 44 dBmV

FDC
Level: -range dBmV (what does range mean?)
S/N: 22 dB

On TV "3", I'm noticing that most channels from 2 through 99 are not showing a picture. Channels with a QAM frequency in the 500s and 600s are showing a picture, but some of them have tiling. Frequencies in the 300s and 800s don't have a picture at all. Channel 110 (Science Channel, QAM Frequency 525.000 MHz) has a lot of tiling, whereas channel 119 (LMN, QAM Frequency 513.000 MHz) seems to be fine. I find that slightly intriguing because 119 is usually the channel that has the most tiling during bad weather when there's an area wide problem.

There are no splitters on the roof, but there is one in the attic. That splitter was replaced between 2004-2006 by a tech, and the original amplifier was installed in 2004. I spoke to a tech a while back who said the line for the upstairs TVs need replacing. I was planning on doing that in January after everything has settled from the holiday chaos.

So does anyone know why I'm now able to view some channels whereas on Wedneday and most of Thursday the signal was so low I couldn't even get a picture?

Cablejim1087

join:2012-09-21
Bath, ME
reply to blu87
As stated above have levels checked from tap to gb to verify good signal then though each leg to each tv. for only three tvs an amp shouldnt be needed. But based on all your notes the wiring could also be the main issue or part of the cause. Most converters will work up to -17 before tiling begins.The one moment please means that channel's frequency is past the -20 range. thats why some channels are there and some are not.Id recommend rewiring to as close to the groundblock you can.


telcodad
Premium
join:2011-09-16
Lincroft, NJ
kudos:15
reply to blu87
FDC is "Forward Data Channel" (from the headend to your STB) and RDC is "Reverse Data Channel" (from your STB back to the headend). Check this post for details on what these all mean/do: »Re: [DVR] cisco rng200n dvr

As far as the differences in reception for different channels close in frequency, a coax cabling/connections issue can cause problems at a certain frequency or range of frequencies. For digital channels, if the QAM carrier used to carry a particular channel happens to fall at that frequency/frequencies, then there could be issues for that channel [and any other channels carried on that QAM carrier(s)] while other channels, carried on carriers outside the problem frequency(ies) may be OK.

Replacing the splitters you can reach and that line for the upstairs TVs may resolve many of your issues.

blu87

join:2004-03-23
united state
reply to blu87
Thanks for the help.

So the tech has been here, fixed the problem and thensome. He tested every connector that he could find. He said that the outside connectors (the ones in that little box attached to the house) were bad so he replaced them. He also removed the amplifier and said I didn't need it anymore. He said something about how Comcast has been doing upgrades and has amplified things on their end, so I no longer needed the amplifier, especially since a connector was bad and was causing the problem anyway. I thought that was slightly odd, because I thought the connectors were just replaced in July or within the past few years. Also, in July I needed to have the amp replaced when it died because there was severe tiling without it. So I guess the connectors were bad then too and weren't checked. I don't know, it's a little weird.

But not only has the problem been fixed, but the two year problem I've had with On Demand is now fixed too. On Demand hasn't worked on the upstairs TVs since a pole was knocked down and replaced two years ago. Comcast always blamed it on the coax cable on the roof and/or never seemed interested in even checking anything out. I always got Error 7 (or maybe it was 14, I can't remember) when trying to view On Demand content and it was never getting an IP address (as shown in the diagnostics screen). But now it works and apparently all this guy did was replace the connectors, and the two previous techs said the line on the roof needed replacing to get On Demand to work again. Wow!

The only bad thing is that the guy wouldn't listen about the splitter in the attic. There was a splitter laying right next to the attic entrance and I told him that was for the antenna, but he insisted it was for the cable. He replaced the connectors on that and now I can view the local ch 26 PBS station on the antenna, so that's good. But I wish he had listened to me and replaced the connectors for the cable line. He probably just didn't want to have to crawl back into the attic, he seemed anxious to get out of here (do I smell or something?).

I'm going to post the new numbers for TV "3" and "2".

TV "3" on Channel 110 (525.000 MHz):

FDC
Level: -9 (white colored)
S/N: 28

RDC
Power: 47

QAM
Level: -11 (still orange)
S/N: 33

-------------------------------------------
TV "2" on Channel 110 (525.000 MHz):

FDC
Level: -3 (white colored)
S/N: 24

RDC
Power: 41

QAM
Level: 0 (white)
S/N: 37

So, I'd say that's an improvement.


telcodad
Premium
join:2011-09-16
Lincroft, NJ
kudos:15
said by blu87:

I'm going to post the new numbers for TV "3" and "2".

TV "3" on Channel 110 (525.000 MHz):

FDC
Level: -9 (white colored)
S/N: 28

RDC
Power: 47

QAM
Level: -11 (still orange)
S/N: 33

-------------------------------------------
TV "2" on Channel 110 (525.000 MHz):

FDC
Level: -3 (white colored)
S/N: 24

RDC
Power: 41

QAM
Level: 0 (white)
S/N: 37

So, I'd say that's an improvement.

Yes, it is. The CH. 110 signal levels and SNRs for the TV "2" STB are now all within their normal ranges, with TV "3" STB's QAM-256 SNR now just up to the minimum (with the signal level just a few dB higher than the -15 dBmV minimum).