Need Help with Behringer T-1953

Discussion in 'rec.audio.pro' started by jd, Sep 1, 2003.

  1. jd

    jd Guest

    Hi,

    My Behringer T-1953, Microphone Pre-Amp suddenly stopped working. I
    replaced the ceramic fuse with an equivalent clear fuse (1 Amp, 250V like
    the specs required), but the unit still does not work.

    Do I definitely need a ceramic fuse or will the clear ones work?

    Any help is appreciated. Thanks.

    John
  2. Mike Rivers

    Mike Rivers Guest

    In article <gTN4b.20519$Go4.19208@lakeread01> jdnorwood@cox.net writes:

    > My Behringer T-1953, Microphone Pre-Amp suddenly stopped working. I
    > replaced the ceramic fuse with an equivalent clear fuse (1 Amp, 250V like
    > the specs required), but the unit still does not work.
    >
    > Do I definitely need a ceramic fuse or will the clear ones work?


    Many ceramic fuses are slow-blowing, which take a higher than rated
    current for a short period of time. You need to determine the type of
    fuse and replace it with a similar one. It may indicate the type of
    fuse on the panel near the fuseholder, or in the manual.

    But is the problem really that the fuse has blown? Occasionally a fuse
    will blow from natural causes, but most of the time if it blows once,
    a replacement will blow also. Fuses are meant to protect the wires
    that go to them so that they don't overheat when something goes wrong
    that makes the device draw excess current. If the fuse blows, it's
    drawing too much current and will continue to do so (and not work
    right) untill you fix what's wrong.



    --
    I'm really Mike Rivers - (mrivers@d-and-d.com)
  3. Pooh Bear

    Pooh Bear Guest

    Mike Rivers wrote:

    > In article <gTN4b.20519$Go4.19208@lakeread01> jdnorwood@cox.net writes:
    >
    > > My Behringer T-1953, Microphone Pre-Amp suddenly stopped working. I
    > > replaced the ceramic fuse with an equivalent clear fuse (1 Amp, 250V like
    > > the specs required), but the unit still does not work.


    Hmmm - you don't say if the original fuse was actually blown !

    If you have a multimeter, check the original fuse. If it conducts - then that
    wasn't the fault.
    If it *was* blown and it blew the replacement too - see analysis below.

    > > Do I definitely need a ceramic fuse or will the clear ones work?

    >
    > Many ceramic fuses are slow-blowing, which take a higher than rated
    > current for a short period of time. You need to determine the type of
    > fuse and replace it with a similar one. It may indicate the type of
    > fuse on the panel near the fuseholder, or in the manual.


    Errr - actually it ain't that simple. Fuses to the IEC spec, which will
    certainly be used by Behringer ( being European ) have specific marking
    regarding their fusing characteristics.

    An example fuse marking goes typically like this F 1A L. Look on the metal cap
    on the end of the fuse. It'll also say 250V too.

    F denotes the fusing speed F= fast T=time delay ( slo-blo in US speak ) FF (
    rare ) = ultra fast, sometimes used to protect sensitive semiconductor devices.
    In theory there's an M ( medium ) although I've never seen one.

    1A = 1 Amp ( or whatever current the number says ) - the design current. IEC
    and US fuses rate the carrying current differently - that's why we say -
    "replace with same type and rating" !

    L = Low breaking current - invariably a glass fuse. H = high breaking current (
    often ceramic but may also be glass with sand fill ). A ceramic body will
    almost never fracture under a fault condition- whereas glass types may do. The
    breaking current rating indicated on the fuse cap is only a recent addition to
    the spec. The required breaking rating is something that needs to be determined
    by the designer of the product - see above -" replace.......


    > But is the problem really that the fuse has blown? Occasionally a fuse
    > will blow from natural causes, but most of the time if it blows once,
    > a replacement will blow also. Fuses are meant to protect the wires
    > that go to them so that they don't overheat when something goes wrong
    > that makes the device draw excess current. If the fuse blows, it's
    > drawing too much current and will continue to do so (and not work
    > right) untill you fix what's wrong.


    Yes indeed. Don't know the product as such - but if the fuse has blown, most
    likely sounds like the power transformer has failed shorted. 2nd guess-
    rectifier(s) after the transformer have gone short circuit.

    Oh - if the fuse hasn't failed - the transformer may have failed open circuit.
    Did it run hot ? Many small transformers have internal thermal fuses that don't
    reset. You can also check this with a multimeter to see if there is circuit
    continuity between the live and neutral on the a.c. input. Expect a 'good'
    transformer to have a primary ( input ) DC resistance of ohms to a few tens of
    ohms. If it's kilohms or more it's 'dead'.


    Graham
  4. Scott Dorsey

    Scott Dorsey Guest

    In article <gTN4b.20519$Go4.19208@lakeread01>, jd <jdnorwood@cox.net> wrote:
    >
    >My Behringer T-1953, Microphone Pre-Amp suddenly stopped working. I
    >replaced the ceramic fuse with an equivalent clear fuse (1 Amp, 250V like
    >the specs required), but the unit still does not work.


    Fuses don't blow for no reason. Fuses blow when something fails.

    >Do I definitely need a ceramic fuse or will the clear ones work?


    The clear one is fine. Is it blown?
    --scott


    --
    "C'est un Nagra. C'est suisse, et tres, tres precis."
  5. jd

    jd Guest

    Thanks, this is *very* helpful. The actual fuse is T 1A H, which is
    explained below. I'll run the continuity check on the ceramic fuse. I did
    not observe any damage visually, but will check with the multimeter.

    The suggestion about the internal transformer is a good one. The unit just
    quit and was not overloaded at the time. I'll check that and let you know.

    Thanks.

    john



    "Pooh Bear" <rabbitsfriendsandrelations@hotmail.com> wrote in message
    news:3F5403FE.3DD310A2@hotmail.com...
    >
    > Mike Rivers wrote:
    >
    > > In article <gTN4b.20519$Go4.19208@lakeread01> jdnorwood@cox.net writes:
    > >
    > > > My Behringer T-1953, Microphone Pre-Amp suddenly stopped working. I
    > > > replaced the ceramic fuse with an equivalent clear fuse (1 Amp, 250V

    like
    > > > the specs required), but the unit still does not work.

    >
    > Hmmm - you don't say if the original fuse was actually blown !
    >
    > If you have a multimeter, check the original fuse. If it conducts - then

    that
    > wasn't the fault.
    > If it *was* blown and it blew the replacement too - see analysis below.
    >
    > > > Do I definitely need a ceramic fuse or will the clear ones work?

    > >
    > > Many ceramic fuses are slow-blowing, which take a higher than rated
    > > current for a short period of time. You need to determine the type of
    > > fuse and replace it with a similar one. It may indicate the type of
    > > fuse on the panel near the fuseholder, or in the manual.

    >
    > Errr - actually it ain't that simple. Fuses to the IEC spec, which will
    > certainly be used by Behringer ( being European ) have specific marking
    > regarding their fusing characteristics.
    >
    > An example fuse marking goes typically like this F 1A L. Look on the metal

    cap
    > on the end of the fuse. It'll also say 250V too.
    >
    > F denotes the fusing speed F= fast T=time delay ( slo-blo in US speak )

    FF (
    > rare ) = ultra fast, sometimes used to protect sensitive semiconductor

    devices.
    > In theory there's an M ( medium ) although I've never seen one.
    >
    > 1A = 1 Amp ( or whatever current the number says ) - the design current.

    IEC
    > and US fuses rate the carrying current differently - that's why we say -
    > "replace with same type and rating" !
    >
    > L = Low breaking current - invariably a glass fuse. H = high breaking

    current (
    > often ceramic but may also be glass with sand fill ). A ceramic body will
    > almost never fracture under a fault condition- whereas glass types may do.

    The
    > breaking current rating indicated on the fuse cap is only a recent

    addition to
    > the spec. The required breaking rating is something that needs to be

    determined
    > by the designer of the product - see above -" replace.......
    >
    >
    > > But is the problem really that the fuse has blown? Occasionally a fuse
    > > will blow from natural causes, but most of the time if it blows once,
    > > a replacement will blow also. Fuses are meant to protect the wires
    > > that go to them so that they don't overheat when something goes wrong
    > > that makes the device draw excess current. If the fuse blows, it's
    > > drawing too much current and will continue to do so (and not work
    > > right) untill you fix what's wrong.

    >
    > Yes indeed. Don't know the product as such - but if the fuse has blown,

    most
    > likely sounds like the power transformer has failed shorted. 2nd guess-
    > rectifier(s) after the transformer have gone short circuit.
    >
    > Oh - if the fuse hasn't failed - the transformer may have failed open

    circuit.
    > Did it run hot ? Many small transformers have internal thermal fuses that

    don't
    > reset. You can also check this with a multimeter to see if there is

    circuit
    > continuity between the live and neutral on the a.c. input. Expect a 'good'
    > transformer to have a primary ( input ) DC resistance of ohms to a few

    tens of
    > ohms. If it's kilohms or more it's 'dead'.
    >
    >
    > Graham
    >
  6. jd

    jd Guest

    OK ... it wasn't the fuse. I got good Ohms out of it.

    I guess the next step is to crack open the box and check the transformer.
    Closer than I was. :)

    John

    "Pooh Bear" <rabbitsfriendsandrelations@hotmail.com> wrote in message
    news:3F5403FE.3DD310A2@hotmail.com...
    >
    > Mike Rivers wrote:
    >
    > > In article <gTN4b.20519$Go4.19208@lakeread01> jdnorwood@cox.net writes:
    > >
    > > > My Behringer T-1953, Microphone Pre-Amp suddenly stopped working. I
    > > > replaced the ceramic fuse with an equivalent clear fuse (1 Amp, 250V

    like
    > > > the specs required), but the unit still does not work.

    >
    > Hmmm - you don't say if the original fuse was actually blown !
    >
    > If you have a multimeter, check the original fuse. If it conducts - then

    that
    > wasn't the fault.
    > If it *was* blown and it blew the replacement too - see analysis below.
    >
    > > > Do I definitely need a ceramic fuse or will the clear ones work?

    > >
    > > Many ceramic fuses are slow-blowing, which take a higher than rated
    > > current for a short period of time. You need to determine the type of
    > > fuse and replace it with a similar one. It may indicate the type of
    > > fuse on the panel near the fuseholder, or in the manual.

    >
    > Errr - actually it ain't that simple. Fuses to the IEC spec, which will
    > certainly be used by Behringer ( being European ) have specific marking
    > regarding their fusing characteristics.
    >
    > An example fuse marking goes typically like this F 1A L. Look on the metal

    cap
    > on the end of the fuse. It'll also say 250V too.
    >
    > F denotes the fusing speed F= fast T=time delay ( slo-blo in US speak )

    FF (
    > rare ) = ultra fast, sometimes used to protect sensitive semiconductor

    devices.
    > In theory there's an M ( medium ) although I've never seen one.
    >
    > 1A = 1 Amp ( or whatever current the number says ) - the design current.

    IEC
    > and US fuses rate the carrying current differently - that's why we say -
    > "replace with same type and rating" !
    >
    > L = Low breaking current - invariably a glass fuse. H = high breaking

    current (
    > often ceramic but may also be glass with sand fill ). A ceramic body will
    > almost never fracture under a fault condition- whereas glass types may do.

    The
    > breaking current rating indicated on the fuse cap is only a recent

    addition to
    > the spec. The required breaking rating is something that needs to be

    determined
    > by the designer of the product - see above -" replace.......
    >
    >
    > > But is the problem really that the fuse has blown? Occasionally a fuse
    > > will blow from natural causes, but most of the time if it blows once,
    > > a replacement will blow also. Fuses are meant to protect the wires
    > > that go to them so that they don't overheat when something goes wrong
    > > that makes the device draw excess current. If the fuse blows, it's
    > > drawing too much current and will continue to do so (and not work
    > > right) untill you fix what's wrong.

    >
    > Yes indeed. Don't know the product as such - but if the fuse has blown,

    most
    > likely sounds like the power transformer has failed shorted. 2nd guess-
    > rectifier(s) after the transformer have gone short circuit.
    >
    > Oh - if the fuse hasn't failed - the transformer may have failed open

    circuit.
    > Did it run hot ? Many small transformers have internal thermal fuses that

    don't
    > reset. You can also check this with a multimeter to see if there is

    circuit
    > continuity between the live and neutral on the a.c. input. Expect a 'good'
    > transformer to have a primary ( input ) DC resistance of ohms to a few

    tens of
    > ohms. If it's kilohms or more it's 'dead'.
    >
    >
    > Graham
    >

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