Noisy (failed) case fan

Discussion in 'TiVo Series3 HDTV DVRs' started by colin1497, Oct 2, 2007.

  1. colin1497

    colin1497 New Member

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    Nov 20, 2006
    OK, I know the case fan is 70mm x 1" (like a cpu fan) and is variable speed. Mine started making noise yesterday. Since I'm 10 months in on my S3, I assume they're using a sleeve bearing fan. Questions:

    1) Anyone else had this happen? You think Tivo will just send me a new fan, I have no problems with replacing myself.

    2) If they did replace your fan, did they do it with another sleeve bearing fan instead of a ball bearing fan? I mean, I'd rather by a GOOD fan than get another free one that will go out after 10 months.

    3) Can't Tivo afford to put decent fans in something that they sold me for $800?

    Colin
     
  2. mpm980

    mpm980 New Member

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    Sep 28, 2007
    I'd say just go out and buy another one. The one supplied by Tivo probably isn't the best anyways. Mine died after two years (I have the typical series 40 hour 2 box though but hardware is hardware) and I replaced it with a typical sleeve bearing but I haven't had any problems with noise at all.
     
  3. Narf54321

    Narf54321 New Member

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    Mar 29, 2005
    I'm pretty sure its the same type of fan (70mm) as used in the standalone series-2 models.

    Tivo would likey want you to send in the whole machine "for repair".
    Check out the aftermakert vendors, such as dvrupgrade.com who also seem to have a supply of fans, as well as Weaknees who also lists compatibility of specific models.

    P.S. I remember a couple years ago trying to find a replacement fan, silent or not, and how difficult it was due to the oddball size.
     
  4. old64mb

    old64mb New Member

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    Apr 11, 2005
    I strongly suspect Tivo will want the $49 for a $2 generic fan (or worse yet, send you a refurb), so might as well DIY. Currently blanking on the really good 70mm fan I put in my last non-watercooled PC, I know there are a couple that are highly regarded.

    When I was upgrading the hard drive last week, I looked at the fan pinout and it seemed to be a standard 2-pin set up which Weaknees seems to confirm with their picture. I was thinking if I was going to swap out anything else, the fan seemed kinda wimpy (and dusty) and you could probably improve the useful life of the rest of the components with a $10 upgrade. I'll try to see if I can track down what I bought before, it was both quiet and moved an awful lot of air.
     
  5. colin1497

    colin1497 New Member

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    Nov 20, 2006
    I had an old 70mm ball bearing fan from an old Athlon MP system and I put it in:

    1) it's higher performance than the stock S3 fan, during boot it starts and max voltage and is pretty loud just from flow. During the boot it lowers the voltage and slows down to the lowest speed and there was a lot of bearing noise, which surprised me, though it is an old fan. I already knew it was not a long term solution and then...

    2) the boot would never complete. Either EMI from the fan or possibly high current draw. Fan draws 250mA max where S3 fan draw 130mA max. Fan connector is located near the power connector and what appears to be a large power bus at the end of the PCBA (not sure how many layers there were on the PCB) but there are no capacitors in the area, so I'm guessing they didn't need to filter anything with the stock fan and this might be the problem.
     
  6. jtown

    jtown New Member

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    Sep 26, 2002
    1) This is two questions. 1a) Not me. And I have a Series 1 that's been running continuously for around half a decade. 1b) Not a chance. "There are no user-serviceable parts inside."

    2) I've had sleeve bearing fans run for years and ball bearing fans die in days. You could put the best fan in the world in there and it might turn out to be a dud.

    3) They did. You got unlucky. They're not going to waste money on LEDs and useless stuff but they're also not going to risk warranty problems by using absolute junk. You got a "decent" fan that happened to die earlier than usual. Be happy it wasn't the hard drive.

    The fan is not variable speed in and of itself. The voltage is adjusted by the tivo based on temperature. Any 12VDC fan should behave in a similar manner. Just get one of the same size/specs and replace the fan making sure to get the + and - correct. Don't worry about whether the fan has a speed sensor 'cause the Tivo can't use it. Only two wires go to the fan. DC+ (variable) and ground. I wouldn't bother with a fan that has a temperature sensor as the S3 will control the speed of the fan using its own temperature sensor.

    As for the boot problem, the power draw could explain it. Since the tivo doesn't monitor the fan speed, the only way it can "determine" whether the fan is functioning properly is to monitor the current draw. Too low= disconnected, too high = jammed/stuck. If you have the same problem with no fan connected, that would support this theory.
     
  7. colin1497

    colin1497 New Member

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    Nov 20, 2006
    Well, after the fan intermittently making noise every few days (mostly at about 3am) I finally got a fan replacement ordered.

    I just installed an "acoustiproducts" AFDP 7025 fan (http://www.acoustiproducts.com/en/acoustifan_dustproof.asp)and have the following comments:

    MUCH quieter than the stock fan. Can't say they're tested the same way, but the fan's rated at about the same airflow as the stock fan, so I shouldn't have given up any high ambient performance but when the system runs the fan at 12VDC at startup it's much quieter than the stock fan was, and when it spools down it's noticeably quieter than the previous fan was (you can't tell from across the room but you can tell the difference sitting next to the Tivo working on it.

    Oh, and it has ball bearings, which I personally like. My company makes fans for airplanes (i.e. fans are actually what I do for a living) and bearings and grease make all the difference in their life, so I don't buy the argument that sleeve bearings (aka bushings) are really an acceptable solution. You can get defective bearings (usually bad grease packing but they can get damaged as well), but really it's a different level of design.

    Tivo boots and works fine with it. For a quiet system I give this fan a thumbs up.
     
  8. jlib

    jlib Lean Forward

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    Nov 21, 2002
    Carmel...
    Oddly, every noisy/failed fan on PCs I have ever had have all been ball bearing. And the quietest and longest lasting ones I have are Papst sleeve bushing models. It probably depends on the quality of of product more than the type of bearing. I suppose the very best would be the new magnetic bearing ones which I haven't tried yet..
     

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