External Cooling Fan

Discussion in 'TiVo Bolt DVR/Streamer' started by thyname, Apr 21, 2019.

  1. BobCamp1

    BobCamp1 Well-Known Member

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    May 15, 2002
    That's not the fan, that's the fan's power supply circuit. If you have one of those loud Tivos and you want it quieter, you'll have to take it apart and come up with a different power source for that fan. Or carefully put a large capacitor in parallel with its power leads. There are other threads about how to replace the fan (even though the fan itself isn't really the problem), which also contain ideas on how to do those things.

    This thread is for people who have quiet Tivos (or who have already made them quiet) and are looking for a little extra cooling capacity.
     
  2. TostitoBandito

    TostitoBandito Active Member

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    Mill Creek, WA
    Ah ok, that makes sense. Thanks for the clarification. I'll dig into the other threads and see about mods.

    It's weird though, because I don't remember my Bolt always being like this. I bought my first Bolt back in late 2016 and it was subsequently replaced by Tivo with a 12/2018 build date unit early this year to fix a wifi issue. I only first noticed the abnormal loudness on this newer unit, and more specifically after the last major software update (the one which brought auto-skip) though that's likely just coincidental. Do we know if they switched components at some point which caused this issue on more recent units but not older ones? It's strange how some would have a PWM buzz and some wouldn't, assuming all components are the same.
     
    Last edited: May 14, 2019
  3. BobCamp1

    BobCamp1 Well-Known Member

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    The prevailing theory is that Tivo switched components or redesigned the fan's power supply circuit at some point. Some have loud units and some do not. I have a loud unit. Putting weight on the Bolt's hump quiets it down a bit for me, though others have said that they can still hear the noise even with the cover completely off.
     
  4. fburgerod

    fburgerod Member

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    Because of the noise, I removed the cover from my bolt and put it on raised 1 inch foot rests. Then I disconnected the fan completely. My temperature range is between 48 and 56 and generally averages around 50 to 52. Totally quiet.
     
  5. jay_man2

    jay_man2 jay_man-also TCF Club

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    Northern VA
    I just got my Bolt earlier this week, and started out with the solution referenced below with the fan on medium. It dropped the ODT from 66 to 57. Today I changed over to have the Bolt sitting on top of this fan on low with the cable card cover off, and the ODT dropped from 57 to 50.

     
    Last edited: May 17, 2019
  6. TostitoBandito

    TostitoBandito Active Member

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    Mill Creek, WA
    Yeah I also have mine sitting directly on top of a 120mm USB fan with the cablecard cover removed and it's around 50-53C most of the time. That said, it doesn't address any of the PWM switching noise/buzz as has been stated above. I'll probably just open the thing up and unplug the internal fan. In an elevated position with active airflow around it I can't imagine it gets very hot even with the fan off. The Bolt has pretty terrible internal airflow, so that fan isn't doing a whole lot. Temperature is probably much more dependent on the ambient temperature of the air surrounding the Bolt, like for instance if it's 25C room temp air being circulated by a fan or if it's 40-50C air in a closed cabinet with no airflow.
     
  7. Mikeguy

    Mikeguy Well-Known Member

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    Perhaps a silly question: how is your fan placed below the Bolt box? Do you have the Bolt resting directly right on top of the fan, so that the fan is acting as a center "pedestal" for the box (and is that working out well balance-wise)? Or is your box supported on the sides by some sort of risers, with the fan, then, in the open space below the Bolt?
     
  8. TostitoBandito

    TostitoBandito Active Member

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    Sep 17, 2006
    Mill Creek, WA
    I have it more or less in the center of the bolt, under the arch. Yes it sort of acts as a pedestal, and the fan is the only thing holding the bolt up (which also does the job of elevating it off the shelf for more airflow). The fan has rubber feet on all the corners so the box sits fine on it with no vibrations or anything. I don't remember whether I have the fan blowing up or down but it probably doesn't matter much. The key is to create some amount of moving air around the Bolt, which it does.

    It's this that I have:

    https://smile.amazon.com/gp/product/B00G05A2MU/

    No complaints. I also got their 2 fan version for my xbox and receiver shelves. It's not a very loud fan. I run them at the medium setting and it's quieter than my Bolt. The max speed setting is probably on par with the Bolt PWM noise, when listening from my couch. You can daisy chain up to 5 of them from a single USB port if you so desire.
     
  9. V7Goose

    V7Goose OTA ONLY and Loving It!

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    New Mexico...
    To get proper cooling with a fan placed on the shelf behind the Bolt, that is not the best design. MUCH better to choose a flat fan where the air is pushed out a port on the thin side of the fan, so that is is concentrated where you need the cooling. This is the best one:
    https://www.amazon.com/dp/B012CL2V3...&pd_rd_r=f71f04c2-7d58-11e9-8ec8-f37f2ab7fd5a

    I have used both types of fans on two different bolts, and there is a huge difference on how efficient the flat blower is, compared to any muffin fan that does not have a concentrated stream of air.

    On a typical Bolt, the coax connection is VERY hot all the time, but when a flat blower is placed near the back of the Bolt as shown in the picture below, with the air sweeping along the back and some blowing under and out the front, there is no detectable heat anywhere on the outside of the Bolt. The metal coax connector acts like a heat-sink to allow that air to suck the heat right out of the box. The ODT on this box is typically at 52. I also found that with this blower, the best cooling is WITHOUT raising the Bolt up off the shelf.

    upload_2019-5-23_7-20-43.jpeg

    That is why I say this is the most simple solution of all - no mods. Just buy the fan, put it on the shelf, plug in the USB connection, and you are done!
     
    Last edited: May 23, 2019
  10. Jim1348

    Jim1348 Well-Known Member

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    Thanks for posting this. I may have to do this, too, with my TiVo Roamio OTA.
     
  11. JoeKustra

    JoeKustra in the other Alabama TCF Club

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    This is good for 4C on my 3TB OTA:
    Fan on Side.JPG
    120mm USB powered.
     
  12. Mikeguy

    Mikeguy Well-Known Member

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    Typo, absent the box being placed outside in the Wintertime? ;)
     
  13. Mikeguy

    Mikeguy Well-Known Member

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    Thanks--interesting approach there! Had been looking at the AC Infinity fans and been thinking of the dual fan version (2 of the 120mm fans pre-strung together), putting one towards/under each side of the Bolt box for cooling as well as balance purposes, but your "pedestal" idea gives another approach to consider. :up:
     
  14. JoeKustra

    JoeKustra in the other Alabama TCF Club

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    Dec 7, 2012
    Ashland, PA...
    Sorry, I should have said "dropped" 4C. On that box, it went from my average 37C to 41C when I added the drive. Plus the room has no A/C. To really cool down a Roamio, I lift the cover on the left side and place a fan blowing air into the box. I can get 25C in a 70F room. I play a lot. :)
     
    Mikeguy likes this.
  15. jlb

    jlb Go Pats!

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    Dec 13, 2001
    Burlington, VT
    Nice to see your TiVoHD still in operation!
     

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