Here's the update. The cable guy came today and replaced both cable cards and tested the signal strength. We still have the same problem; we are missing most channels above 100. A few do work, though. The cable box downstairs works fine and receives all channels. What else could it be besides the Tivo unit?

Should we do a complete reinitialize, which would require getting him back here to pair the cable cards again? Or should we send the box in to you?

You can't just install new cards and expect it to work. Is the cable guy calling the cable co and giving them all of the information necessary to authorize the cards and your box? you might want to call the cable co and verify that the data they have for your TiVo (data id, host id, etc.) are the same as what your TiVo reports in the cable card troubleshooting page.

Yes, I observed him calling the technical service at Comcast and reading off all of the data from the TiVo. After that, the unit could tune in the channels 2-100 and a handful higher than that. The person on the other end seemed very knowledgeable about TiVo and asked which model we had and how long it had been since guided setup.

Failing to get channels above 100 sounds very much like a CableCARD issue. You might want to call the cable co and make sure yourself that they have the data exactly as it reads on your TiVo CableCARD screen.

We've tried four cable cards and they all exhibit the same symptoms. Remember, the error is, "Searching for signal on: Cable In." The cable cards determine which channels are authorized (HBO, SHO, etc.), but they are not tuners.

I went through every channel to get a better idea of which ones are returning this error.

Of the low channels, we get errors on 15-23, 47, and 96. In the 200 range, we correctly receive 208, 216, 239, 240, 247, 251, 258, and 283. But we get errors on 200-207, 209-215, 217-238, 241-246, 248-250, 252-257, 259-282, 284, 285, 295-297.

For the music channels 501-546, we get errors on all but 506, 507, 522, and 532.

If I try to tune a channel which we are not supposed to get, TiVo displays the error, "Channel not available." That's because the cable card is correctly preventing authorization on that channel based on our subscription.

If the problem is not the cable cards, then what's left besides the TiVo unit?

After 2.5 years, and 10 pages of posts, is there a final word on this?
My TivoHD restarts/reboots once or twice a week.
I have one M-series card, an upgraded 1TB internal hard drive, a tuning adapter, a Tivo branded USB WiFi adapter, an LCD TV, and Time Warner cable service with a very strong signal.

At this point, after all of the software fixes over the years, if you're running current software (version 11 or later) then the rebooting is usually indicative of a bad hard drive. We have replacement TiVo HD hard drives that should fix the problem.

Are there any tests that I can do on the hard drive to verify that it is the problem? My Tivo and the WD hard drive I installed myself are both less than a year old. I bought the TivoHD in January 2009, and I installed a new WD10EADS in March 2009. Is the theory that the drive came bad, it went bad after I installed it, or does this model drive have issues in Tivos?

No - that model doesn't have inherent drive issues.

Information on testing your drive is here:

http://www.wkforums.com/forums/showthread.php?t=9

Just be aware that drives that pass manufacturer's tests can often fail under the stress of the video environment. The manufacturer's tests just aren't as rigorous as a TiVo.

Series 3 replacement machine

After 3 replacements for my series 3, tivo said they would replace the latest problem machine with a tivo hd. They would not let me replace it with an hd xl. Did I complain to the wrong person?

Those machines aren't hugely different, save for the drive space. If the unit you're getting is brand new, and if they aren't charging for the swap, that doesn't sound like an unreasonable deal.

TIVO HD series three slow freezing grey screen etc.

After about a year of flawless tivo 3 performance, I was just about to buy a second unit for the bedroom to replace the HD cable dvr, but all of a sudden the tivo started doing all kinds of weird things. turn on the tv and get a grey screen where the remote doesn't work. yellow light going on signifies it is getting the signal from the remote. So I rebooted it by unplugging the cord. Then it started getting really slow in response to the remote. then it would just freeze. hitting the remote would result in 3 or 4 minutes before it would move the tivo.
I have read some of the posts and it is not the cablecards, since this has nothing to do with the cable service.
The disk is quite full and has been since I got it. I have the external hard drive which is brilliant. It deletes programs as needed.
I don't see how increasing the RAM would make a difference since it has been this way since I got it.
The configuration has been exactly the same since I set it up, so interference would not be a possibility.
Tivo cust svc doesn't open for another two hours or so, I have to wait.
Help.

Sounds to me like one of the drives is failing. We'd recommend a larger internal replacement - and then not re-using the external drive.

Replacement drives are here:

http://www.weaknees.com/s325.php

S3 Pixelation and Reboots

I recently had an issue with pixelation and eventually rebooting with my Series 3 TIVO. After almost 3 years of flawless service and heavy daily recording, I started getting pixelation - mainly on HD channels. After rebooting, I could get by without problems for about half an hour initially, but eventually I started to get repeating unsolicited reboots. I had an external WeaKnees drive attached, so quickly removed but still had the problem. If I removed the cable from TIVO, the reboots stopped. This allowed me to run through the TIVO internal tests, which all passed (including 54). I could also watch recorded material (HD) in this configuration without incident. This led me to believe the hard drive wasn't bad, and that I had other problems. After a couple of calls with TIVO tech support, they convinced me I needed a replacement unit. Upon arrival of the replacement S3, I took a day off just in case the cable card pairing didn't go well - which it didn't. After twelve hours with Insight Communcations techs (I'm convinced they tried everything the knew how to do), we couldn't pair the cards with the replacement box. After another two hours on the phone with TIVO, they finally took the unit back and refunded my money. They also reinstated my dead S3, which has a lifetime contract. This still didn't address my problem, which brought me to this forum. Long story short (too late) - I replaced the internal hard drive with a Weaknees replacement 250 gb drive and now I am back up and running with no problems (cable cards paired in well under an hour). I have yet to hook up the external drive again - I'll give things another week or so before proceeding to this step.

Two things of note for people struggling with this problem:
1. The TIVO internal tests don't appear to be 100% accurate. I'm sure these tests are very useful for diagnosing problems, but the passing results were clearly inaccurate (and confusing) in my case.
2. If I had it to do over, I would have tried the hard drive replacement option first - before going for a replacement unit. I'm kicking myself for the time I burned trying to get this problem sorted out.

Right - tests that show failed drives, clearly mean drive problems.

Tests that show drives passed do NOT necessarily mean the drives will work perfectly. The drive tests are not as harsh on the drive as the everyday operation of the TiVo. So drives that pass the tests may still not work perfectly - we see that all the time.

As far as trying a replacement drive option first, I'm often stuck thinking about the quote "to a hammer, everything looks like a nail." We sell drive replacements first and foremost, so we do think they fix most problems, and they really do fix the majority. But there are other problems with TiVos. Still, something like 90% of TiVo problems involve bad hard drives.