Interesting Power issue

[Doug Brott]

I have added a second HR20 to my bedroom. It is currently a temporary situation, but will likely stay this way for another 6 months or so.

The interesting thing is that since I added this second system I have a very odd problem. On one of the HR20s, the remote control stops working when the television is turned on. Both systems are in IR mode and the same HR20 has problems. Obviously it complicates changing the channel or using the menus when the remote control does not work. If I turn the TV off, the remote control starts working again.

Does anyone know why I may be seeing this? I was going to put a meter on the power source but I can't find my meter right now :lol:. Other than perhaps poor voltage control, I was wondering if anyone had thoughts.

The two HR20s are stacked (just like in the family room) and the TV is about 6-12 inches away (corner of TV to back corner of HR20 stack) with the HR20s just below the bottom of the TVs.

I have my workaround, but this seems very bizarre to me.

[Earl Bonovich]

There is a problem, where some HR20's get just enough IR interfearence from neary by TV display units.

Try sliding your HR20's back a bit, so that there is a barier between them and the TV display.

Or just to test the theory, a piece of cardboard next to the HR20's to block the TV screen picture to the IR sensor.

[Doug Brott]

There is a problem, where some HR20's get just enough IR interfearence from neary by TV display units.

Try sliding your HR20's back a bit, so that there is a barier between them and the TV display.

Or just to test the theory, a piece of cardboard next to the HR20's to block the TV screen picture to the IR sensor.

Thats a thought .. I'll give it a try.

[Lee L]

Well, it says you have HR20-700s and the RF actualy works on those and you surely know about it so why not use that?

What kind of TV do you have? Plasma and LCDs are much worse for this than other types. I have a remote IR setup and had to buy a different IR receiver when we added an LCD.

[Doug Brott]

The TV is a 26" LCD .. I'll try the "shield" first and see if it makes a difference. If it does, then I'll have to play around with the stack to find a working solution. I'll check out RF as well, but it's funny trying to switch modes when I can't use the remote :). I'll let you know my results later tonight.

[d0ug]

The TV is a 26" LCD .. I'll try the "shield" first and see if it makes a difference. If it does, then I'll have to play around with the stack to find a working solution. I'll check out RF as well, but it's funny trying to switch modes when I can't use the remote :). I'll let you know my results later tonight.


I have read that IR can be a problem with plasma sets. It sounds like it is EMI created by the high voltages in the actual plasma panel. The EMI gets inducted into the IR detector circuitry on poorly designed IR detectors. This was a problem with the newer HD Tivo units.

Never herd of it with LCDs, but I suppose the high voltage inverters for the CCFL bulbs could be radiating some kind of EMI.

[LarryFlowers]

Doug... you're not alone!!

My new Samsung 4665 LCD does this to me every day. When I wake, I turn it on and go for the coffee, in about 10 minutes I will be able to use the remote without further problems.

I tried shielding the sensor, didnt work, and I can't move the unit due to space limitations. My H20-100 is in same place and is on RF and works fine so I usually use it at first then switch to the HR

Its very annoying!:nono2:

[d0ug]

Doug... you're not alone!!

My new Samsung 4665 LCD does this to me every day. When I wake, I turn it on and go for the coffee, in about 10 minutes I will be able to use the remote without further problems.

I tried shielding the sensor, didnt work, and I can't move the unit due to space limitations. My H20-100 is in same place and is on RF and works fine so I usually use it at first then switch to the HR

Its very annoying!:nono2:


Fortunately I am not having this problem, I have only read about it.

Since this seems to be an EMI issue, shielding the sensor with cardboard or something similar to block light isn't going to help. You need something that can block radio frequencies. The easiest solution for EMI interference is to just increase the distance between the device being affected by the EMI and the device creating the EMI. Or put your DVR in a faraday cage.

[Doug Brott]

Fortunately I am not having this problem, I have only read about it.

Since this seems to be an EMI issue, shielding the sensor with cardboard or something similar to block light isn't going to help. You need something that can block radio frequencies. The easiest solution for EMI interference is to just increase the distance between the device being affected by the EMI and the device creating the EMI. Or put your DVR in a faraday cage.

I might try some tin-foil formed in the shape of the DIRECTV logo :p

Distance will be my first try, but I am space limited to some degree.

[d0ug]

I might try some tin-foil formed in the shape of the DIRECTV logo :p

Distance will be my first try, but I am space limited to some degree.

I not any kind of RF engineer or anything, so I am not 100% positive this will work, but you may be able to try shielding your shelf.

I don’t know what kind of setup you have your TV on, but if it is one of those typical TV stands with the shelves underneath, you could try putting a layer of aluminum foil on the bottom side of the shelf that the TV is sitting on. If you do a good job taping it up there, most likely no one will be able to see it is there, then run a simple grounding wire from the aluminum foil to the screw holding on an outlet cover. This should ground the entire foil "shield" and hopefully absorb some of your EMI

If anything it costs you nothing but time to try.

I seem to remember reading about people doing this when they would run dual CRT monitors next to each other. The EMI from the monitors would cause noise and distortions in the adjacent monitors sometimes. People would cut a piece of cardboard large enough to isolate the 2 monitors, wrap it in foil, ground it with a simple wire going to the outlet screw, and then place it between the monitors.

[Doug Brott]

Well, the TV is hanging on the wall .. Turns out that by adjusting the brightness and contrast level, I was able to minimize the effect. I never moved the equipment. I still get no response from the HR20 just as the TV is powered on, but within seconds it starts working again.

I think in the past maybe after 20 minutes it would start working a little, but more recently I've never been patient enough to verify that fact.

Moral of the story .. lower the contrast & brightness if there is a problem.

As an aside, a sweatshirt placed over the front (glass portion) of the LCD actually provided enough shielding. Sweat shirt on .. remote works .. sweat shirt off .. remote fails. It was quite funny if I wasn't really trying to solve a problem.

[d0ug]

Well, the TV is hanging on the wall .. Turns out that by adjusting the brightness and contrast level, I was able to minimize the effect. I never moved the equipment. I still get no response from the HR20 just as the TV is powered on, but within seconds it starts working again.

I think in the past maybe after 20 minutes it would start working a little, but more recently I've never been patient enough to verify that fact.

Moral of the story .. lower the contrast & brightness if there is a problem.

As an aside, a sweatshirt placed over the front (glass portion) of the LCD actually provided enough shielding. Sweat shirt on .. remote works .. sweat shirt off .. remote fails. It was quite funny if I wasn't really trying to solve a problem.


Hmm interesting about the sweater, sounds like it might have something to do with the light coming off the panel. I doubt a sweater is going to do much to block EMI, unless its woven out of steel wool =P

[veryoldschool]

Well, the TV is hanging on the wall .. Turns out that by adjusting the brightness and contrast level, I was able to minimize the effect. I never moved the equipment. I still get no response from the HR20 just as the TV is powered on, but within seconds it starts working again.

I think in the past maybe after 20 minutes it would start working a little, but more recently I've never been patient enough to verify that fact.

Moral of the story .. lower the contrast & brightness if there is a problem.

As an aside, a sweatshirt placed over the front (glass portion) of the LCD actually provided enough shielding. Sweat shirt on .. remote works .. sweat shirt off .. remote fails. It was quite funny if I wasn't really trying to solve a problem.
Had this with my "new" Sony [see sig]. Lost the MCE 2005 IR remote senor.
Changing the "power saving" options on the Sony would "fix it". I ended up changing the location of the IR sensor instead.
Use RF mode for my D* stuff.

[houskamp]

Hmm interesting about the sweater, sounds like it might have something to do with the light coming off the panel. I doubt a sweater is going to do much to block EMI, unless its woven out of steel wool =P
That was my thought too..
have you tried putting black tape over the IR sensor? maybe the reciever is somehow still breifly looking at the IR during power on?

[Lee L]

When I had the issue, I also noticed that it got better after a few minutes. I guess the backlight in the LCD must give off extra IR until it is fully warmed up.

I see your point about switching to RF being difficult as you do need to read the numbers off the screen to to it.

[veryoldschool]

I see your point about switching to RF being difficult as you do need to read the numbers off the screen to to it.
But you could to it the "old school" way:
Use the front panel to navigate to the instruction screen, then write them down, turn off the TV and go through the steps to change to RF. Once the receiver starts too blink [responding to remote] then you can turn the TV back on.

[Doug Brott]

But you could to it the "old school" way:
Use the front panel to navigate to the instruction screen, then write them down, turn off the TV and go through the steps to change to RF. Once the receiver starts too blink [responding to remote] then you can turn the TV back on.

Or I could cover it with my sweat shirt :lol:

Yeah, I definitely reduced the backlight and that may have been the real solution .. It's funny that it only affected one of the receivers. I was probably at just the "wrong" distance away based on the frequency of the light. Reducing the backlight probably changed the frequency just enough to make a difference.

[armophob]

A tin foil hat may help as well.:)

[mertzf]

My thoughts: the LCD TV is emitting IR as it turns on. Case in point: my MBR TV is FLAT on the wall, facing the bed. On the wall opposite to the TV, there is a picture frame, with a glass front, pretty much parallel to the TV. In order to make the old Tivo work from the closet (no line of sight), I bought an Radio Shack IR repeater (captures the IR from the remote, and repeats it in the closet). I noticed that every time I turn the TV on, the capture part of the repeater lights up like crazy, as if I kept pushing on a remote button. It usually goes away in a few seconds.

In your case, I would try to diminish the TV IR from feeding back into the receiver IR sensor. Maybe you have glass the IR could bounce off of. Maybe you want to put your TV at more of an angle on the wall (tilting mount). Also, you may want to try putting the sweater on things around the room that could reflect the IR (picture frame, furniture, you get the idea...) to identify the source of the reflection. Best of luck.

[Lee L]

I noticed the same thing with my IR repeater - the talkback light was lit like crazy. However, even with it mounted on the back of hte TV and facing up toward the ceiling and hte TV angled slightly down for optimal veiwing, enough IR hit it to mess it up, until I changed to a CFL friendly IR receiver.

As far as one being a problem, it could also be that part or installation tolerances cause one to be more suceptible than the other.

[veryoldschool]

Or I could cover it with my sweat shirt :lol:

Yeah, I definitely reduced the backlight and that may have been the real solution .. It's funny that it only affected one of the receivers. I was probably at just the "wrong" distance away based on the frequency of the light. Reducing the backlight probably changed the frequency just enough to make a difference.
My MCE 2005 IR pickup can be moved around very easily. It seemed to be most affected when "in plane" with my display. I found that my speakers [the big old stereo days type] would block it enough so everything is still "in plane", so TV -> Speaker -> IR pickup, would still let me keep things where they needed to be. Before with my CRT RPTV, I could have it on top or right next to it. It took me a few "hoops" before I found what the problem was when I changed TVs. The IR receiver does have a red light when triggered that "finally" [blamed Microsoft at first :lol: ] let me trace the cause.

[rsonnens]

I once had a problem like this with my H10, the problem ended up being cased by another remote (a non-dtv remote) in the room that had something on top if it keeping a button permently pressed. It was under a pile of 'junk'.

[Doug Brott]

I once had a problem like this with my H10, the problem ended up being cased by another remote (a non-dtv remote) in the room that had something on top if it keeping a button permently pressed. It was under a pile of 'junk'.

I actually did have this problem with my garage door at one point .. Finally realized it when I found the old remote in the garage and took it out. The garage door would sometimes open, sometimes not .. once the offender was removed, all was good.

[Moocher]

I remember this was discussed on the avsforum.com. Wish I could remember a key word for you to use for a search. I think the key will be positioning/shielding.

If my wife's IBM laptop is pointed toward my IR repeater it goes nuts. If my Macbook is pointed toward the repeater, nothing happens. Hmmm.

Mooch

Mooch

[bakers12]

The problem is IR interference, not EMI (RF). You need to block the light, so cardboard, etc. will work fine. You don't need foil because you're not blocking EMI.

[Stuart Sweet]

I'm curious what color the sweatshirt is. I'm guessing green or blue. Something that reflects green or blue absorbs red and probably infrared as well.

If you took a piece of green cardboard (again the goal is to absorb red) and put it between the HR20 and the TV I wonder if it would do the same.

[veryoldschool]

This is IR, not sure if short or long wave, but I need to use the metal of my speakers to block it. Two 3/4" high density particle board sides of my speaker has no effect.
From this I doubt cardboard will work. "Tinfoil" seems to be a better option. [OK when was the last ime anybody had "tinfoil"? :lol: ]

[cartrivision]

Hmm interesting about the sweater, sounds like it might have something to do with the light coming off the panel. I doubt a sweater is going to do much to block EMI, unless its woven out of steel wool =P

The problem most likely has to do with the IR light that the TV screen emits. I have an IR repeater and the activity indicator will light up if I position it where it has a direct "view" of my TV screen, but I don't have any problems with IR from the TV interfering with my IR receiving devices under normal placement conditions... except when I first turn on my TV (a Samsung 40” LCD).... then the TV evidently temporarily emits an excessive amount if IR, because the indicator light on my IR repeater that is placed behind the TV screen will stay lit up for about 30 seconds after the TV is first turned on.

[Doug Brott]

The problem most likely has to do with the IR light that the TV screen emits. I have an IR repeater and the activity indicator will light up if I position it where it has a direct "view" of my TV screen, but I don't have any problems with IR from the TV interfering with my IR receiving devices under normal placement conditions... except when I first turn on my TV (a Samsung 40” LCD).... then the TV evidently temporarily emits an excessive amount if IR, because the indicator light on my IR repeater that is placed behind the TV screen will stay lit up for about 30 seconds after the TV is first turned on.

This sounds like what the problem is, except that the "30 seconds" was more like 10-20 minutes .. hence the problem. By reducing the backlight, it decreased that delay down to less than 10 seconds which is tolerable. It's not like I turn the TV on and off all of the time :p.

[Doug Brott]

I'm curious what color the sweatshirt is. I'm guessing green or blue. Something that reflects green or blue absorbs red and probably infrared as well.

If you took a piece of green cardboard (again the goal is to absorb red) and put it between the HR20 and the TV I wonder if it would do the same.

The sweatshirt was red, but it effectively blocked out the light from the TV altogether, so I'm not sure color played a part in this or not.