Posted: Sat Dec 04, 2021 3:29 Post subject: BCM4709 Temperature
Hi,
I have a Netgear R8500, with a CPU BCM4709 at 1400MHz, temperature of 75 degrees and room ambient at 20 degrees. I tried to find the max temp specifications online, but without success. Within 90 degrees everything should be ok, right? I can also see that on the board, there is a 4 pins serial connector, can be used for add a fan? if yes, at which voltage? wee have a pin map? thanks
Joined: 08 May 2018 Posts: 14125 Location: Texas, USA
Posted: Sat Dec 04, 2021 4:22 Post subject:
I can't seem to find a datasheet anywhere, either; but you are within specs. I would still opt for some kind of cooling and airflow to allow for maximum heat dissipation, though. Maybe a USB-powered fan pulling air through the top of the case. _________________ "Life is but a fleeting moment, a vapor that vanishes quickly; All is vanity"
Contribute To DD-WRT Pogo - A minimal level of ability is expected and needed... DD-WRT Releases 2023 (PolitePol)
DD-WRT Releases 2023 (RSS Everything)
----------------------
Linux User #377467 counter.li.org / linuxcounter.net
I can't seem to find a datasheet anywhere, either; but you are within specs. I would still opt for some kind of cooling and airflow to allow for maximum heat dissipation, though. Maybe a USB-powered fan pulling air through the top of the case.
Tks for your reply. Ok, I would like to keep cables inside the enclosure, with a tiny fan. Checking for the voltage of that serial port. Should be 5V max.
Joined: 08 May 2018 Posts: 14125 Location: Texas, USA
Posted: Wed Dec 08, 2021 7:59 Post subject:
Looks like it already had some sort of header fixture to plug into; not sure if these have a cooling fan already provided. Would be great to have a link to where you go the image/information... _________________ "Life is but a fleeting moment, a vapor that vanishes quickly; All is vanity"
Contribute To DD-WRT Pogo - A minimal level of ability is expected and needed... DD-WRT Releases 2023 (PolitePol)
DD-WRT Releases 2023 (RSS Everything)
----------------------
Linux User #377467 counter.li.org / linuxcounter.net
Looks like it already had some sort of header fixture to plug into; not sure if these have a cooling fan already provided. Would be great to have a link to where you go the image/information...
It's a Chinese second hand products app, so there aren't specifications. But I just installed a small 3v fan, 70 degree, not so much difference
Joined: 31 Jul 2021 Posts: 2146 Location: All over YOUR webs
Posted: Fri Dec 10, 2021 14:23 Post subject:
Dust is a nice insulator, so anything coated in it will be nicely snug and warmer, fyi,
I use carbon coated aquarium foam and a fine filter foam around a thin layer of the aquarium foam placed where the air intakes are, and over the fan itself, I use a flex filter airflow is not impeded and the amount of dust is kept to a minimum ripe for yearly maintenance schedule.
While most specs allow for some high temperatures, TBH the greatest silicone killer is heat, shortens the life span considerably. Dust contributes to this over time.
I also replace thermal compounds for a higher performer.
Now if you added a fan and the best it does is 70 from 90 then theres something not right, replace the thermal grease and check the heatsinks are flush and not warped or not making appropriate contact.
Also that heatsink groves where the fan blows into are not optimal for air cooling, so the fan is far too close to the groves and only most effective area is where the fan is right over and to the bottom, leaving the lef/right are barely getting any air flow due to how the run vertically and to left/right should be horizontal so air can travel outwards in all directions.
Problem here is also if there is no source of cool air to the back of the fan on the case, consider pulling air in not pushing air in install to test how that performs..
My router however (different from yours) has external fans pushing air in, through the filter material. I will consider adding internal fans when I can take it out of commission long enough as its the main router.
Joined: 08 May 2018 Posts: 14125 Location: Texas, USA
Posted: Fri Dec 10, 2021 15:41 Post subject:
It would have been better to use an actual photo from the R8500 as shown from the results from FCC ID search. Anyhow, if you're going to use a 12v slimline fan, you may want to tap into the power input buss(es) to get maximum efficiency. USB power will work, but it limits things some. It is really fun modifying router cases (that require it). One thing I like about the Linksys WRT AC series is that all you need to do is add one or two USB-powered fans pulling air up and through the case and done. No hack jobs required. You can also use a laptop cooling fan on some cases when you wall mount them to draw air up through the case. _________________ "Life is but a fleeting moment, a vapor that vanishes quickly; All is vanity"
Contribute To DD-WRT Pogo - A minimal level of ability is expected and needed... DD-WRT Releases 2023 (PolitePol)
DD-WRT Releases 2023 (RSS Everything)
----------------------
Linux User #377467 counter.li.org / linuxcounter.net
But I just installed a small 3v fan, 70 degree, not so much difference
was the casing still opened or already closed after you mounted the fan? it can be because there's no airflow (the vents on the plastic casing are too narrow) and the hot air keeps circulating inside the casing.
Another possibility is bad thermal paste/thermal pad.
probably all these reasons... there is not enough space between the chassis and the fan that's already a small one. Also I replaced the thermal pads, but not enough. Thanks
Dust is a nice insulator, so anything coated in it will be nicely snug and warmer, fyi,
I use carbon coated aquarium foam and a fine filter foam around a thin layer of the aquarium foam placed where the air intakes are, and over the fan itself, I use a flex filter airflow is not impeded and the amount of dust is kept to a minimum ripe for yearly maintenance schedule.
While most specs allow for some high temperatures, TBH the greatest silicone killer is heat, shortens the life span considerably. Dust contributes to this over time.
I also replace thermal compounds for a higher performer.
Now if you added a fan and the best it does is 70 from 90 then theres something not right, replace the thermal grease and check the heatsinks are flush and not warped or not making appropriate contact.
Also that heatsink groves where the fan blows into are not optimal for air cooling, so the fan is far too close to the groves and only most effective area is where the fan is right over and to the bottom, leaving the lef/right are barely getting any air flow due to how the run vertically and to left/right should be horizontal so air can travel outwards in all directions.
Problem here is also if there is no source of cool air to the back of the fan on the case, consider pulling air in not pushing air in install to test how that performs..
My router however (different from yours) has external fans pushing air in, through the filter material. I will consider adding internal fans when I can take it out of commission long enough as its the main router.
Take care.
Thanks for the detailed answer. Probably right know I can not pretend, but for sure I need to reopen it, remove the small installed fan, pretty not useful, replace all the conductive parts and reshape the chassis.
It would have been better to use an actual photo from the R8500 as shown from the results from FCC ID search. Anyhow, if you're going to use a 12v slimline fan, you may want to tap into the power input buss(es) to get maximum efficiency. USB power will work, but it limits things some. It is really fun modifying router cases (that require it). One thing I like about the Linksys WRT AC series is that all you need to do is add one or two USB-powered fans pulling air up and through the case and done. No hack jobs required. You can also use a laptop cooling fan on some cases when you wall mount them to draw air up through the case.
Yep, I was thinking to buy a laptop cooling base, but as you said, on some way is fun to mod electronics... this router in my idea have a lot of potential, limited by thermals. So I just would like to reach at least optimal temps. Thanks for now
I opened this baby again and removed the fan I added previously. Removed the big black heat sink. Then I removed also the aluminum lid on the CPU part (yellow area, tks to TweakTown for the pic) and replaced the old thermal pad with a 5mm grey one, directly in contact with the big black heat sink, without the aluminum lid. For now, after 34 minutes of uptime, room temp 19C degrees and CPU temp 64C degrees. Let's see
the aluminum lid is for RF shielding, so probably it's better (for nearby electronic equipment, living beings, and for the router itself) to fill the gap between the chip and the lid with thermal pad, and keep the lid closed, instead of removing it.