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Tivo cooling project / Quiet Tivo

Discussion in 'TiVo Coffee House - TiVo Discussion' started by lasitter, Dec 10, 2012.

  1. unitron

    unitron Active Member

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    Apr 28, 2006
    semi-coastal NC
    Maybe in his church they'll let him get by with just sprinkling.
     
  2. MeInDallas

    MeInDallas Member

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    Jul 31, 2011
    Dallas, Texas
    I never thought of that :eek:
     
  3. MeInDallas

    MeInDallas Member

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    Jul 31, 2011
    Dallas, Texas
  4. slowbiscuit

    slowbiscuit FUBAR

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    Sep 19, 2006
    In the ATL
    This has to go down as one of the best OCD threads ever.
     
  5. lasitter

    lasitter New Member

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    I was looking for a 50->40 fan adapter (would mount internally), but 50mm is such an oddball size there's sadly nothing for it.

    As to external powering, one of the things I'd love to know is what kind of safety margin the Tivo power supply already has. It dissipates 26 watts when it's working, but and it make a few watts to spare? If so, the replacement fan could run on the standard power supply.
     
  6. lasitter

    lasitter New Member

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    Oct 27, 2010
    It's the computer server background! :)
    What I've ordered will be using 3M 8815 Thermal Tape ...

    Enzotech BMR-C1 VGA Cooler
    Enzotech MOS-C1 C1100 Forged Copper Heatsinks
    Enzotech MOS-C10 C1100 Forged Copper Heatsinks only
    Enzotech CNB-R1 Forged C110 Pure Copper Heatsinks only

    I'll probably use a physical mount for the big heatsink on the Broadcom chip.

    Two of the four Micron 9WG27 128MB DDR2-800 system memory chips are apparently mounted on the bottom side of the board.

    Don't know what you could do to cool them better ...

    I also don't know if there's any room under the HDD for the chips under there.

    A lot will depend on the temperature returned by the laser meter.

    I do have one, and it's a fun gadget. I definitely plan to used one ...

    Will do.
     
  7. lasitter

    lasitter New Member

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    Most CPUs also throttle back if they start getting to hot. I wonder how quickly the fan spins up to prevent that. Any throttling to control heat could show up in system performance.
     
  8. lasitter

    lasitter New Member

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    Oct 27, 2010
    This is awesome. Don't know how I overlooked it. Think I'll have to try this out!
     
  9. unitron

    unitron Active Member

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    Apr 28, 2006
    semi-coastal NC
    Which is why the guy I linked to had to go the custom fabrication route.

    But I was thinking putting the fan on the outside would let you use a bigger, slower, quieter fan.

    It would also be an interesting experiment to see if one could mount outside and blow in (which would allow use of a snap-on filter which could be periodically cleaned) and still get the needed cooling.

    Using internal power for something externally mounted introduces not only "does the supply have the capacity" but the "how to run the wire from inside to outside", and a wall wart solves both problems.

    Any fan you could fit where the original internal is mounted probably isn't going to bring the TiVo power supply to its knees.
     
  10. lasitter

    lasitter New Member

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    Oct 27, 2010
    I feel like an idiot for not noticing this before ...

    [​IMG]

    If you bring the picture up to maximum size, it gives you the power supply spec right there on the PCB ...

    42.48w

    That's lots more than the total unit max draw of 26w I'd seen quoted elsewhere.

    I just got in three of the IP Queen fans, and they look very similar to the COFAN. If these specs are right, I should be in business ...

    50 x 50 x 25 mm Ball Bearing
    12VDC Operation Voltage: 6.0~13.8
    VDC Rated Current : 0.25A
    Rated Speed : 2600 +/- 10% RPM
    Air Flow : 28.00 CFM
    Static Pressure : 3.2 mmH2O
    Noise Level : 26 dBA
    Weight : 44g

    Double the airflow at 2600 vs 3500 RPM?? We'll see.
     
  11. scn101

    scn101 New Member

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    I bought a replacement Cofan and found it still quite noisy. If I hold the fan in my hand it is fairly quiet but once attached to the Premiere there's kind of a roaring noise. I tried using O-rings on the screws to isolate it from the chassis but that only helped a bit.

    So how quiet are the IP Queen fans? Better than the Cofan, or the same?

    Thanks.
     
  12. MeInDallas

    MeInDallas Member

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    Jul 31, 2011
    Dallas, Texas
    The IPC Queen one is way quieter for me. Maybe because its ball bearing, and the Cofan ones are sleeve bearing, not sure.
     
  13. scn101

    scn101 New Member

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    Aug 13, 2013
    Plano, TX
    Ok, thanks for the very speedy reply! I ordered one and will report back.


     
  14. MeInDallas

    MeInDallas Member

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    Jul 31, 2011
    Dallas, Texas
    Oh and when you get it, if you use the Tivo screws, screw them in really REALLY slow, or just use the ones that come with the fan. The first one I got, I cracked the side of it because the Tivo screws are so fat :D
     
  15. scn101

    scn101 New Member

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    Aug 13, 2013
    Plano, TX
    I received the IPC Queen fan and unfortunately I found it to be louder than the Cofan.

    I did find a way to make the Cofan quieter. Someone suggested removing the label on the Cofan, removing the rubber plug, and adding an oil/grease mix. I did that but observed no real change to its volume.

    Then I decided to push the fan blades off their spindle. Using both thumbs through the housing the blade assembly slid off revealing the sleeve bearing. I oiled and greased it, ensuring the oil went between the sleeve bearing and the spindle. I then reassembled it by pushing the blade assembly back on the bearing and mounted it back into the Tivo using O-rings on both sides of the screws to isolate the fan from the box as much as possible.

    Now the Premiere is quiet. I can still hear the fan moving air but no other obnoxious fan sounds so that's good enough.

    BTW, I tried pushing the fan assembly off the IPC Queen to lube it as well but it simply broke, :(
     
  16. unitron

    unitron Active Member

    16,389
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    Apr 28, 2006
    semi-coastal NC
    When actually removing the blade and shaft assembly from one of those fans, you have to remove the label on the part that doesn't turn, remove the plug, if any, and then there will be a little C ring or O ring type washer that snaps into a groove on the shaft, and it needs to be carefully removed and will jump across the room and disappear forever if you give it the chance.

    Once you get that off, you should be able to pull the blade hub and shaft assembly out of the bearing easily.

    There should be no reason to remove the shaft from the blade hub as they don't turn independently of each other.

    You might need a Q-tip and some denatured alcohol or lighter fluid to remove the old lubricant to see that little clip in the first place.
     

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