I have seen reports of slow menus on my type of box (VIP722) and I simply mentioned I have not experienced it with the box plugged directly into the wall. I also have never had it freeze or reset, or do anything else "common" with DVRs in general. Also, my channel changing goes very quickly in relation to some complaints, as it typically takes about a second to change from one channel to another. Long story short, a receiver, like any computer, requires power to think as well as to do. If it does not have that power, or has a limited amount available to it, cannot think or thinks very slowly (in the case of "low" power). Bringing up the guide (a lot of information, especially on a DVR) without enough power can take it a long time to do, relatively speaking. Also things like changing channels, navigating menus, and buffering live TV can be a problem (“freezing”). If you want the long story long, read on.
Example: Laptop computers typically have a power management setting that reduces the amount of power they use when not connected to a power outlet. In the reduced performance mode (typically called "Power Saver") it draws less power. When plugged into a wall, a laptop can run at full tilt because it has a steady charge being put back into the battery. When unplugged it goes to the "power saver" mode (although that can be overridden in the settings) so that it conserves battery power by lowering the brightness of the screen and limiting CPU time (causing applications to run slower). Bringing that back to the receiver, it will operate on less power but the CPU cannot designate the full processor time and power to an application (the guide in your case).
I want to be clear that not all power issues present themselves in the same manner. Some cause hard drives to be inaccessible or "freeze" when buffering, some present themselves as slow channel changing, and some are the slow appearance of the guide. The constant "resetting" of a receiver is also a battle to get more power where it needs to go and it resets "thinking" that that will give it the juice to move past the point where it stopped thinking previously. Again, the myriad of issues that can occur due to low power or a temporary or long term "brown out" condition are not limited to one specific symptom or symptoms in a particular order. Each box deals with it individually with "expected" outcomes (“known receiver issues”) and not "specific" ones.
A little deeper into power limitations, we get to actual power availability. Most modern home power circuits are capable of handling 120V at 15 to 20 amps (older homes are less, as service to the entire home can be 50 amps- I learned from my recent “power” upgrade). Although the voltage can stay pretty close to that 120V mark over multiple plugs, the current drawn by each device is limited by the number of devices drawing power. As I mentioned in the original post, if there is a large TV it will draw a large amount of power (X) on start-up and then require less to continue operating after it warms up (X+ in the event of a similar size plasma). Note: The circuits in your house should run at about 20% (I guess that number depends on who you ask) less then the specified rating for the circuit when applied to continuous loads or the breaker will trip. = 120V is constant (with any luck) and the amperage is limited (16 amps if on a 20 amp circuit). 16 amps needs to power all the devices connected to that circuit continuously. So your TV takes X, the receiver takes Y and any remaining devices take Z divided by the number of devices (no specific order btw, as a larger power supply will generally be able to draw more power then a smaller one). Depending on the equipment, you may have to move devices to another plug to give them sufficient power to operate (and prevent the circuit breaker from tripping). For an added point of reference, coffee makers typically blow a fuse at 10 amps.
Now, toss in a surge protector or power strip. They split the "limited" amount of power available at the outlet and possibly limit that power more to protect your gear from "surges" over a certain draw (sudden increase in amperage, usually "detected" in less expensive ones by temperature). The series of outlets are limited as to how much power they get by the circuit in the strip. A power conditioner isolates each plug and only allows a certain amount of power at each “type” of plug and it is usually labeled what device will plug in where to get the proper power and is usually filtered to prevent noise from one device (DVD/CD players and stereo equipment) from entering the other circuits (and has been proven to improve picture quality in the process). Again, even with a higher dollar strip or a full on power management system, the power is still limited which can lead to the problems described above and in other threads. All of this translates to one amount of power available (X) and a slightly larger amount (Y) of draw required to operate at 100% capacity.
Side note: I had a laugh at this, but if you read ANY of the "instructions" on proper usage of a strip or surge protector device, they actually suggest unplugging the device in an electrical storm (lightening still kills them whether they are the $6 or $10,000 jobbies).
A seemingly easy question to answer and I wrote a novel, yet again, to provide as much detail as I can about possible causes of receiver issues. Sorry for the long-winded read, but I wanted to explain as much as I could rather then just saying “because”. Am I saying that everyone experiencing issues like these are subject to power limitations? Not at all. I am simply saying that the possibility is there and bypassing the strip to give the receiver its own power CAN rectify many situation. Consider it an explanation of the former troubleshooting steps we would use when troubleshooting, and the logic behind them. Hope this makes sense.
