Additional information. As a test, last night I scheduled a recording for early this morning. The (surprising) outcome:
So the problem is local, not network.
That's pretty much how they bricked mine about a year ago. Suddenly couldn't close a recording session and rebooted after a Navigator upgrade losing whatever it was attempting to record. Got a 4k box for 1 year free (after which the usual extortionate price will apply). I have another 8642 which I also own and is, strangely enough, slightly older than the one they assassinated and it still works though it's quite slow. Might be time to negotiate a new box. Alternately you can argue with them for months like I did and chances are good you're going to waste a bunch of time with technicians coming out only to find they can't do anything. I'm OK with the new box even though it's ultimately going to cost me money. Seems nothing in a networked world lasts for very long.
Just in case someone else has the same problem:
Technician coming in two days. Will know more then.
Technician came today, and solved my problem by switching the input from HDMI to coaxial cable, saying that I would notice a slight degradation in picture quality. Needless to say, as soon as he left, I immediately switched back to HDMI...
So, end of story: I am stuck with this (having to pull and reconnect the HDMI cable) unless I buy a new PVR. The technician also said that he had seen this problem before, so I am not alone in this situation.
At little late here.. but it does sound like its a HDMI handshake issue.
As stated above, I would try another HDMI cable if you have one to test with.
As well, I have seen some weird things between some different TVs and other devices period.
Many TVs now try to do all the 'specialty' stuff that HDMI can do now. ARC, CEC, etc.
Sometimes these can cause weird issues with some devices. I know my TV was acting weird with my AVR when I had ARC on and tried to use it.
Turn off the other HDMI features may help?
Yes, when I had my chat session with Rogers support, he did suggest trying another cable. I actually had one on hand (a defective one, with degraded picture quality, but it does work, just poorly). There was no difference. Still lost signal.
The fact of the matter is that this problem started with the firmware upgrade. There is no way around that. And the technician did say that he had seen other cases like mine (which is why he came prepared with a coaxial cable!), so it is defintely not a random isolated problem.
Unsure what you're saying - you have a "defective" HDMI cable on hand which you switched in? The fact that you're having different results with different HDMI cables reinforces the likelihood that your box or TV is having an HDMI handshake issue - buy a couple of new HDMI cables (can get good quality very cheap online at Monoprice.com, for instance.
@JCGB : I agree with @343sj and others who have suggested an HDMI handshake issue. Although this started for you with the firmware update, which may have precipitated the issue, HDMI could still be your problem. I have the following questions/suggestions.
1. What is the length and gauge of your HDMI cable? If 28 ga and longer than 10', that could be the source of the problem.
2. Try turning on the TV first, then the STB. If you have an AVR in the loop, turn it on first, then TV, then STB, waiting a few seconds between each when testing.
3. What STB output setting are you using? Are you using "Auto"? Under Settings - Appearance, TV Type, try selecting something like 1080i, or 1080P instead of auto.
Here's an FAQ on HDMI issues: As mentioned there, and by others, try turning off HDMI-CEC on your TV/AVR if applicable.
As I suggested earlier, it could still be a signal issue. Have you actually checked your signal recently?
Lastly when you say you have "no signal" is that what it says on the TV? If so, that could still indicate a connection issue between the STB and the TV (like HDMI handshake). Have you tried a different HDMI input on the back of the TV/AVR?