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PSU Fan Direction

Discussion in 'Electronic Repair' started by Caroline, May 14, 2004.

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  1. As for
    I got the terminology mixed.

    Choke it up to the always infamous brain-fart. - Reinhart
     
  2. I have always found ACF/ACF2 chipped Rockwell/Conexant "hard" modems
    Cool. I've not had that much luck with Conexant myself. But, my experience
    with them is limited.

    Texas Instruments, on the other hand... - Reinhart
     
  3. Caroline

    Caroline Guest

    Responses to Frank and Asimov follow, along with a few more general
    observations.

    From an Earthlink technician, September, 2003:
    --------
    1. Go to Control Panel
    2. Double click Dial-Up Networking icon.
    3. Click the Connection icon. Right click to display "Properties." Choose
    "Properties."
    4. Click through General, Configure, Connection, Advanced.
    5. Uncheck the box next to "Use Error Control." Click OK
    6. Click "Options."
    7. Click "Bring up terminal window after dialing. Click OK. Click OK.
    8. Double-click the Connection icon.
    9. Click the Connect button. Type user names and passwords as needed.

    Under normal circumstances, after the login information has been transmitted,
    you will see a message that says, "... starting PPP session." If you see a large
    amount of "garbage" characters underneath this line, then most likely there is
    some sort of interference on the phone line. Try connecting a different phone
    cord from the wall to the computer. If you are using a splitter, try the
    connection without the splitter. Contact your local phone company to conduct a
    test of the lines.
    -----

    Six months ago I did indeed get a large amount of "garbage" characters.
    Ultimately an Earthlink tech. and I blamed it on changing weather conditions
    over a week-long period in my area. This past winter I didn't have the
    disconnect problems I have today. I did another phone line check as described
    above recently and again got a lot of garbage characters.
    Noted. Thanks.
    Okay.

    Per your other post that talked about obtaining the last call diagnostic report:
    I am using the directions at http://www.modemsite.com/56k/x2-hyperterm.asp and
    http://www.modemsite.com/56k/usehyper.asp
    to try to obtain this but so far no luck. I'm having problems at about step 5 of
    the first site. But I'm unfamiliar with a lot of what exactly this is doing, so
    I'll keep studying it, experimenting and trying.


    Asimov:
    I saw your comment about dirty RJ phone connections and will look into this.
    Also, I understand about not telling the phone company I'm having modem
    problems. Just say I hear noise and echoes on the phone line...

    Going back to another conflict in this thread, and for what it's worth:
    While my professional technical experience is not specialized to computer
    hardware design, I do have power plant experience. I absolutely agree with those
    saying that a computer power supply improperly electrically sized (e.g. watts
    rating too low) may very well
    cause computer freeze-ups. When a power source is overloaded, its output voltage
    will
    fall and potentially to a point that equipment it feeds will not operate
    properly. Transients will be different and potentially detrimental when the
    power supply is undersized. And so forth. I can't believe anyone with a real
    technical background seriously disputes this.

    With a PSU now twice the size of the original one, I am not getting the freeze
    ups I used to get before. Before, I had to tread carefully before bringing up a
    few applications simultaneously and quickly, due to seeing lock-ups before. Or I
    avoided doing this at all. Now it seems I can start up as many applications as I
    would ever want, as quickly as I want, and I do not get lock-ups.

    Re the operating temperature of the CPU: Of course Ricky and others are right
    that an overheated CPU (or other accessories) may detrimentally affect overall
    computer
    performance. Supercooled conductors are not being installed in certain, larger
    electrical power applications just to waste money, and so forth. I'm not even
    countenancing the one (I think) post that claims otherwise.
     
  4. w_tom

    w_tom Guest

    Your (exampled) system was not running at 100% fine. It
    crashed - one machine instruction did not process properly -
    when peripheral load increased. System must work just fine
    with all peripherals being accessed. And for most desktops,
    that is 250 watts. You call it frozen or crashed. I also
    call it 0% performance. The machine is 100% defective because
    insufficient power caused a computer crash. Machine worked at
    100% until power was insufficient; then failed. Did not slow
    down. It crashed. That is a 100% defective machine.

    But back to the orginal post which cites a completely
    different concept. Let's say that power supply is sufficient
    for motherboard but not sufficient for motherboard and
    peripherals. An earlier poster said the motherboard will
    process instructions faster if the power supply is sized
    larger. No, CPU either processes instructions at 100% speed
    or it crashes; for either supply. A larger supply does not
    make the CPU execute faster - as another would have us
    believe.

    Same for temperature. Another suggested that if CPU got
    warmer, then it might process slower. Again, nonsense.
    Either that CPU works at 100% or heat creates timing changes
    inside CPU: machine instruction no longer executes properly.
    Machine works at either 100% or it crashes, freezes, works at
    0%.

    Many might say the problem is opening Explorer only because
    they made a conclusion based only upon observation. That is
    the formula for disaster. They said the same thing about
    Challenger (it launched last time at below 32 degrees;
    therefore will always launch fine at that temperature). It is
    a basic concept of science that does not change even for
    computers. The concept demands knowledge both from underlying
    theory AND from experimental evidence. Anything less is
    characteristic of a junk science conclusion.

    To say Explorer crashed the system and to not first collect
    basic facts is classic junk science. It was not Explorer that
    caused the crash. It was an insufficient power supply whose
    failure was not noted until after Explorer was started.

    IOW a computer expert first learns basic electrical
    principles - understand both the underlying theory and has
    associated real world evidence. Having both learned those
    principles and having experience by personally building
    computers (at the IC level - not assembling a computer), then
    I have long understood how heat and insufficient power can
    crash computers. Also learned how to avoid those problems in
    advance by using engineering principles and math, and by
    taking data with appropriate tools.

    Nothing in a power supply or in temperature will make a
    computer execute faster (ignoring, for the moment, protection
    circuits found in Intel processors). Either it runs at 100%
    or it crashes.

    Suggested here is that the earlier poster said something
    different from what your example demonstrates. A probable
    reason for confusion or misunderstanding?
     
  5. w_tom

    w_tom Guest

    The fastest way to identify an undersized power supply is to
    load up many tasks simultaneously - to access many peripherals
    simultaneously. Then monitor DC voltages with a 3.5 digit
    multimeter. No appreciable voltage drop should be measured;
    voltage should not drop into the lower 1/4 of limits if supply
    is sufficiently sized.

    A major difference exists between super cooled verse a
    semiconductor running at cooler room temperatures. Currently,
    supercooled conductors are only for superconductivity - to put
    more power through smaller wires (ie Detroit Edison). Totally
    irrelevant to computers and semiconductors. In power
    transmission systems, a cooler wire can carry more current.
    Again completely irrelevant to how fast a CPU works.
    Furthermore, a CPU cooled too much can fail. Digital
    electronics have both an upper limit and a lower limit for
    proper operation. Heat does not make digital electronics
    faster or slower.

    Concerning step 5 of the Hyperterminal procedure at
    http://www.modemsite.com/56k/x2-hyperterm.asp :
    Instead of entering just AT, enter AT&F . IOW modem may
    respond to commands but not echo them back to screen, or be
    setup for other responses. Enter AT&FL3DT. Modem should at
    least sound dial tone on speaker or (very faintly) click an
    off hook relay.

    Again, you want to test modem with a direct connection into
    NID; modem connection not via existing household phone wires.
    You must confirm problem is on their (telco) side; not on side
    of NID that you are responsible for.
     
  6. Franc Zabkar

    Franc Zabkar Guest

    Of course cooling a chip is important, but there comes a point where
    factors other than temperature will limit performance gains. For
    example, the capacitance of a p-n junction will limit the switching
    speed of a logic gate.


    - Franc Zabkar
     
  7. Franc Zabkar

    Franc Zabkar Guest

    Actually, those "garbage" characters are probably legitimate binary
    data which make up the PPP packets. In fact you should see these same
    characters with EC (error correction) enabled.

    As I understand it, after an initial text based login sequence, the
    dial-up session switches to binary PPP mode. This means that any
    strange characters received during the username and password phase are
    genuine garbage, while those received after the session switches to
    PPP mode may or may not be so.

    In any case, a better test for line quality is to enable EC and then
    query the modem's last call diagnostic report. The modem will tell you
    how many "I-frames" were transmitted and received, and how many of
    these resulted in errors. On a good connection I get about 1 error in
    1000 packets, while on a bad connection I can get as many as 1 in 20.
    You can minimise the error rate, and therefore maximise your
    throughput, by limiting the modem's max connect speed.

    See http://www.modemsite.com/56k/x2-linklimit.asp

    BTW, if you choose to disable EC, you can get an idea just how noisy
    your last connection was by viewing the total CRC errors in your
    ppplog. Note that in the case of external serial modems some of these
    CRC errors may be caused by serial buffer overruns.

    See http://www.modemsite.com/56k/ppp.asp

    Have you enabled command echo with ATE1? Until you do this, you may be
    typing blind.

    BTW, if you wish to retrieve the modem's last call diagnostic report,
    avoid using the AT&F command just prior to doing so. On some modems
    this will reset the diagnostic data. On others, like my own
    Rockwelloid, AT&F resets the "reason for disconnect", but leaves the
    data intact.

    I have to wonder about how PSUs are rated. Your initial post stated
    that your PSU was a 90W device which, at face value, seems seriously
    low. But then I doubt that many, if any, PC PSUs actually deliver
    anything near their claimed output. In fact I've only ever heard of
    one PC PSU that even regulates properly. By that I mean that the vast
    majority of PSUs "regulate" by taking a weighted average of the +5V
    and +12V rails, and then assume that the other supply rails will fall
    within spec solely on the basis of their turns ratio. A poor design,
    IMHO ...


    - Franc Zabkar
     
  8. Caroline

    Caroline Guest

    C wrote
    snip but comments noted
    Evidently. No idea how to enable anything. I need to dig into this a lot more.
    (It's probably way more efficient for me to do this than to have you
    troubleshoot via an internet forum, though your trouble is appreciated.)
    I haven't given this another shot yet but likely will sometime in the next few
    months.

    Seems like most of my disconnects occur when I'm typing a long email or Usenet
    post. I've checked my Outlook Express settings and some other modem-related
    setting involving being "idle," but no luck.
    No, I think it's right. This was and still is a very barebones computer. I don't
    do video games. I have only a single hard drive, CD-Rom drive, and floppy drive.
    Nothing else extraordinary at all.

    The old power supply has a label on it that says the max. output is only 70
    Watts. This contrasts with what Gateway and other sources say about it being a
    90-watt power supply. Probably a little semantical distinction about "power
    rating."
    This would be consistent with what I say above.
    Haven't looked at this.
     
  9. Ricky Eck

    Ricky Eck Guest

    Ok, this MAY be a possability. SOME IP's reserve the right to "Disconnect"
    you if your connection is idle for a certain, prederterminad amount of time.
    I.E. NetZero would disconnect me after two hours if there was "No User
    Signal" sent. What that ment, is if I was not actualy typing in a web page,
    or something like that, it concidered me idle. Even if my mail was checking
    every 10 min. I use a program called "TrackPass", through RealOne. It is
    for my racing, that gives me real time stats during a Cup Race, and Time
    Trials. Anyways, NetZero did not count this as a "User Signal", mainly
    because the computer was doing all the transmiting. It was computer
    generated. How in the world it knows this, I don't know. But it does. I
    don't know how many times, during the short time I used dial-up between my
    moves, that my TrackPass got shut down, because NetZero dissconected on me
    (unlimited internet, my Butt, and don't get me started on that stupid
    HighSpeed Junk they offer..:). Now, is this the same problem for you? I
    don't know. Could be. I don't know how long a "Long Email" is. However, I
    would look at your TOS provided by your ISP, and see if this could apply.
    Just an Idea.
    This may be an idea. The 70 Watt may be RMS, and 90 Watt PTP? (Many Amps
    claim this, 100 watts, then you look in fine print "PTP", RMS is actualy
    like 75 Watts or some other number. Just made a number up) Or, Gateway may
    have screwed ya..:) LOL Na, a major company screwing a Cust. It could
    never happen. I know I have a Gateway, and I am happy with it so far. No
    Probs, and have had it for about 1.5 years. Just hope it stays that way.
    My Mom has a Dell, and had nothing but Probs with hers.

    Rick
     
  10. Caroline

    Caroline Guest

    I don't think this is what is happening. I'll get thrown off the connection
    after maybe 20 minutes of typing an email or Usenet post.

    I am trying to get people off this problem because, with all due respect and
    affection for the great analyzers, engineers, and technicians in the world, you
    can't be aware of the nuances to my problem. Like I bought the house (where my
    computer now is) in August of last year. The disconnect problems started in
    September. They went away as the weather seemed to change. Then they returned
    about a month ago (after we had mega-rain, which has stopped, but... ). Prior to
    August, in my former residence, I had not had disconnect problems. I have not
    been monkeying with the software. So yes it may very well be my new
    (10-year-old) house's phone line problems... Some of you are no doubt slapping
    your head as you speak, and hopefully killfiling this thread at this point ;-)
    Sorry. I find it hard to convey every detail in these posts. It's why I tried to
    keep the threads narrow. I really just wanted to know whether reversing the fan
    direction had ever been a problem in anyone's experience! :)

    BTW The fan flow reversal does not seem to be a problem. I'm still gonna buy a
    little heat sink fan, as Ricky and others I think suggested, sometime soon, as I
    figure at a minimum it might help the overall life of the CPU.

    Aside: Someone asked about how often I clean the inside of the case and its
    hardware. Answer: About once a year. Any more often and there wouldn't be much
    to clean.
    snip

    Oops. I made a mistake. The nameplate on the old power supply says: "max.
    combined power on +5V & +3.3V output is 70 watts." But as I'm sure you know,
    there's a +12 Volt output, too. On my computer this output is rated at 1.5 A.
    This of course is an additional 18 Watts. Thus the nameplate also says "90 W.
    Max." (Close enough.)
     
  11. Ricky Eck

    Ricky Eck Guest

    I wasn't tring to drag the post, I just seen you post that you got booted
    off after writing a long letter. That popped into my head that NetZero used
    to do that.

    Rick
     
  12. Caroline

    Caroline Guest

    [After installing a power supply twice the watt rating of the old power
    supply--]
    To be complete, I have an update:

    I switched to the integrated modem ("56K AC-Link Voice Modem") two days ago. I
    also switched the telephone access number I use with Earthlink. My rate of
    disconnects has gone down considerably--only one in the last 2.5 days, vs.
    half-a-dozen or more daily in the recent past. (My time on the computer and
    typing messages did not change notably in the last 2.5 days.)

    I'll switch back to the external modem soon and see if the problem was a
    "crowded" (or otherwise deficient-in-some-way) access number.
     
  13. w_tom

    w_tom Guest

    Did you make the direct connection to NID - to determine if
    noise is from internal or external source? Demonstrated is
    one modem that tends to be more noise resistant (has a better
    DSP algorithm) than the other. Test still does not identify
    source of noise and resulting disconnect. You still have
    disconnects. Therefore you are not yet identifying reason for
    failure. Long before we discuss fixing the problem, first
    concentrate on identifying the problem. Hyperterminal has
    always been a powerful tool for identifying a modem verse line
    problem in part because it is so simple to use and because it
    provides fundamental facts without the summarizations (basic
    data removed) from Windows.
     
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