Strange cooling/power issue

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markc6123

Occasional Visitor
Greetings. My RT-AC86U typically runs around 90 degrees C. As it's warmed up and gotten hot and muggy outside, it's started running at 95c. I put a USB fan in back to blow over the vents and got it down to 63c. However, I have an HD Homerun connected to the router. (HD Homerun is a device with an antenna connected to it and broadcasts the signal over the network). As soon as the fan is turned on, I lose the signal for all local channels except for the strongest one. I've tried plugging the fan into other outlets, both on the same circuit and not, same result. I can put a battery operated fan there and have no issues. Other network connections are fine, NAS/Nvidia Shield/Roku TV's etc. I rebooted the router while it was in it's chilled state, and the HD Homerun. No joy. The HD Homerun sits on the shelf below the shelf with the router and fan on it. I tried putting the HD Homerun in an anti static bag that computer cards ship in. Still no joy.

I'm on an AI mesh with wired backhaul and could move the Homerun to the node but that's less than ideal, I finally have my cabling situation right where I want it.

What in the wide world of sports is going on here? Thanks in advance.
-Mark
 

markc6123

Occasional Visitor
Greetings. My RT-AC86U typically runs around 90 degrees C. As it's warmed up and gotten hot and muggy outside, it's started running at 95c. I put a USB fan in back to blow over the vents and got it down to 63c. However, I have an HD Homerun connected to the router. (HD Homerun is a device with an antenna connected to it and broadcasts the signal over the network). As soon as the fan is turned on, I lose the signal for all local channels except for the strongest one. I've tried plugging the fan into other outlets, both on the same circuit and not, same result. I can put a battery operated fan there and have no issues. Other network connections are fine, NAS/Nvidia Shield/Roku TV's etc. I rebooted the router while it was in it's chilled state, and the HD Homerun. No joy. The HD Homerun sits on the shelf below the shelf with the router and fan on it. I tried putting the HD Homerun in an anti static bag that computer cards ship in. Still no joy.

I'm on an AI mesh with wired backhaul and could move the Homerun to the node but that's less than ideal, I finally have my cabling situation right where I want it.

What in the wide world of sports is going on here? Thanks in advance.
-Mark
Edit- I looked up "homemade farraday cage", lined some aluminum foil with saran wrap, and wrapped the Homerun in that. Still no joy....
 

heysoundude

Very Senior Member
you're getting power for the fan from the USB port on the router? It might be the fan motor itself, but I also seem to recall something about USB interference...
Go to Advanced/Administration/System and check your USB setting - is it set to USB 3.0? and is the HDHomerun unit on the 2.4GHz band? Hover your mouse over USB mode and click for some insight
 

markc6123

Occasional Visitor
you're getting power for the fan from the USB port on the router? It might be the fan motor itself, but I also seem to recall something about USB interference...
Go to Advanced/Administration/System and check your USB setting - is it set to USB 3.0? and is the HDHomerun unit on the 2.4GHz band? Hover your mouse over USB mode and click for some insight
Right now it's connected to the USB 2 port on the router. I had previously tried USB 3 as well. It doesn't matter where the fan is plugged in, I've tried other nearby USB ports as well as direct connect to different wall outlets. The Homerun is hardwired to a switch. I tried direct connecting to the router. I changed the USB connection to USB 2 only, didn't work. When I change the USB setting in the router the Homerun drops off the list entirely and I have to re-boot it or disconnect/reconnect the ethernet.
 

OzarkEdge

Part of the Furniture
Greetings. My RT-AC86U typically runs around 90 degrees C. As it's warmed up and gotten hot and muggy outside, it's started running at 95c. I put a USB fan in back to blow over the vents and got it down to 63c. However, I have an HD Homerun connected to the router. (HD Homerun is a device with an antenna connected to it and broadcasts the signal over the network). As soon as the fan is turned on, I lose the signal for all local channels except for the strongest one. I've tried plugging the fan into other outlets, both on the same circuit and not, same result. I can put a battery operated fan there and have no issues. Other network connections are fine, NAS/Nvidia Shield/Roku TV's etc. I rebooted the router while it was in it's chilled state, and the HD Homerun. No joy. The HD Homerun sits on the shelf below the shelf with the router and fan on it. I tried putting the HD Homerun in an anti static bag that computer cards ship in. Still no joy.

I'm on an AI mesh with wired backhaul and could move the Homerun to the node but that's less than ideal, I finally have my cabling situation right where I want it.

What in the wide world of sports is going on here? Thanks in advance.
-Mark

Where is the antenna located? How are you measuring channel signal strength/reception? Perhaps you need a pre-amp on the antenna to boost signal strength.

Are you viewing TV on a weak 2.4 mobile device? The fan may be degrading a marginal WiFi signal at the router. A 5.0 WiFi device is recommended for steady tuner performance. A 2.4 WiFi device is often not fast enough for stable viewing... depends on ambient conditions.

Set the router USB port to 2.0 mode even though no EMI emitting high frequency data comms is happening with a fan.

Try moving things a bit and confirm the antenna coax cabling and connectors are good quality and preferably routed directly with few connectors/splitters to preserve signal strength. Antenna location and orientation is critical for maximizing signal reception... a few inches or degrees can make a big difference.

My HDHomeRun tuner is wired to my media center switch off the router. Two outdoor antennas in the attic are combined and pre-amped over coax to the tuner. No issues except the dodgy on-screen channel selector.

As for the AC86U... install/reset/configure the latest firmware to be sure the CPU wait state is enabled for better cooling... and whatever else Asus did. Mine run at about 82-85c... tolerable.

OE
 

OzarkEdge

Part of the Furniture
When I change the USB setting in the router the Homerun drops off the list entirely and I have to re-boot it or disconnect/reconnect the ethernet.

I wonder why a router USB setting affects the tuner Ethernet connection?

OE
 

markc6123

Occasional Visitor
Where is the antenna located? How are you measuring channel signal strength/reception? Perhaps you need a pre-amp on the antenna to boost signal strength.

Are you viewing TV on a weak 2.4 mobile device? The fan may be degrading a marginal WiFi signal at the router. A 5.0 WiFi device is recommended for steady tuner performance. A 2.4 WiFi device is often not fast enough for stable viewing... depends on ambient conditions.

Set the router USB port to 2.0 mode even though no EMI emitting high frequency data comms is happening with a fan.

Try moving things a bit and confirm the antenna coax cabling and connectors are good quality and preferably routed directly with few connectors/splitters to preserve signal strength. Antenna location and orientation is critical for maximizing signal reception... a few inches or degrees can make a big difference.

My HDHomeRun tuner is wired to my media center switch off the router. Two outdoor antennas in the attic are combined and pre-amped over coax to the tuner. No issues except the dodgy on-screen channel selector.

As for the AC86U... install/reset/configure the latest firmware to be sure the CPU wait state is enabled for better cooling... and whatever else Asus did. Mine run at about 82-85c... tolerable.

OE
Thanks for the tips. Router has always run a bit warm, and always has the latest firmware. To make matters worse, I just upgraded the firmware on the Homerun and now can't tune anything, good Lord.
 

markc6123

Occasional Visitor
I wonder why a router USB setting affects the tuner Ethernet connection?

OE
My thought as well but I'll try anything at this point. Once I get the tuner working again after firmware "upgrade" I'll try moving it to the node....
 

markc6123

Occasional Visitor
Thanks for the tips. Router has always run a bit warm, and always has the latest firmware. To make matters worse, I just upgraded the firmware on the Homerun and now can't tune anything, good Lord.
I'm watching on a hardwired Nvidia Shield TV
 

OzarkEdge

Part of the Furniture
I'm watching on a hardwired Nvidia Shield TV

How does media streaming from the TV tuner over the network to your screen device... use another media streaming device like the Shield TV?

I watch network tuner TV on various mobile devices using the HDHomeRun Android app.

But we digress.

OE
 

markc6123

Occasional Visitor
How does media streaming from the TV tuner over the network to your screen device... use another media streaming device like the Shield TV?

I watch network tuner TV on various mobile devices using the HDHomeRun Android app.

But we digress.

OE
The Shield has the HD Homerun app but I don't like it, preferring to use the native Android TV app, or my Plex server. When I tried the Homerun app on my PC it didn't change anything. I did pull the below from the Homerun forums in response to another person with the same issue. I found it interesting. The person with the issue could plug whatever the offending device was anywhere in the house and it would throw off the Homerun. Tomorrow I'll try moving the Homerun to the mesh node and see if that helps anything.....

It's called impulse noise, and it can come from a variety of sources. The biggest culprits are fluorescent lights (especially cheap CFLs), dimmer switches, some LED light bulbs (mostly cheap Chinese shirt), and anything that converts electricity into motion, including fans, motors, pumps, and compressors. It will often get worse as the components age. This is the same thing that those of us who are old enough will remember would make the TV go all fuzzy on Saturday morning cartoons when mom would start vacuuming in the living room. In the digital world, instead of fuzz, you get breakups and loss of signal.

Ferrites may or may not make a difference (probably not), but the best thing is to just put as much distance between the offending object any any part of the TV reception (antenna/cable/splitters/HDHomeRun) as possible.
 

OzarkEdge

Part of the Furniture
The Shield has the HD Homerun app but I don't like it, preferring to use the native Android TV app, or my Plex server. When I tried the Homerun app on my PC it didn't change anything. I did pull the below from the Homerun forums in response to another person with the same issue. I found it interesting. The person with the issue could plug whatever the offending device was anywhere in the house and it would throw off the Homerun. Tomorrow I'll try moving the Homerun to the mesh node and see if that helps anything.....

It's called impulse noise, and it can come from a variety of sources. The biggest culprits are fluorescent lights (especially cheap CFLs), dimmer switches, some LED light bulbs (mostly cheap Chinese shirt), and anything that converts electricity into motion, including fans, motors, pumps, and compressors. It will often get worse as the components age. This is the same thing that those of us who are old enough will remember would make the TV go all fuzzy on Saturday morning cartoons when mom would start vacuuming in the living room. In the digital world, instead of fuzz, you get breakups and loss of signal.

Ferrites may or may not make a difference (probably not), but the best thing is to just put as much distance between the offending object any any part of the TV reception (antenna/cable/splitters/HDHomeRun) as possible.

I doubt a 5vdc PC fan 'motor' is disrupting anything with EMI or power disturbances. A decent antenna signal over coax is immune from external noise.

Since your fan is causing issues, I'd solve the router CPU 90+c issue by servicing or replacing the router before or after it malfunctions, heating-wise. The current fan solution is apparently not good enough.

OE
 

markc6123

Occasional Visitor
Apparently the fan can cause issues. I plugged it in in the bathroom, away from the router and Homerun, and sure enough, it disrupted the TV signal but not as severely. Why would I service/replace something that isn't broke? Temperature issues are common on this router, be glad you don't have it. I was about to move the router and attach it to the node instead, thought I'd run the cable straight to the Homerun instead of splitting it. Problem solved. Looks like the "impulse noise" was affecting the splitters or something. At any rate, all good now. Interesting mystery to fish through though.
 

gattaca

Senior Member
I and many others written about the nasty interference generated by cheaply made switching PSU as well as even "LED nightlights". CFLs are a common offender as are many LED lighting fixtures. An earlier poster alluded to the same issues. Believe it or not, these things can generate huge amounts of electrical noise and RF! BLUF: Look for something from a reliable manufacturer like Apple, Belkin, etc.. and something that is really UL listed.

I cannot follow the entire conversation but I'd try using a well made PSU for the fan. If you moved it to battery, that's a big clue so it's either the PSU being the root-cause or the 5V fan is horrible electrical noise maker. Change one or the other or both.

If you think all USB power supply units are made equally well, then have a look at these postings: Some of these are *(@*@ right dangerous -> https://lygte-info.dk/info/ChargerIndex UK.html

I have a rule now that anything coming into the house gets tested and if it generates too much line noise, back it goes. Why? B/C my house uses the electrical system as a communications plane / platform - yeah it's old but it still works - like me. ;)
 
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