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Carver DTL-100 CD Player dropped dead

Discussion in 'Solid State' started by CavScout, Dec 8, 2018 at 11:34 AM.

  1. CavScout

    CavScout Well-Known Member

    Messages:
    578
    Was listening to my Carver CD player with no problems and it just stopped .......no power !

    I opened it up and did not see a fuse.
    Any experts out there know what could be the problem or if there IS a fuse ?
     

     

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  2. Bob

    Bob AK Subscriber Subscriber

    Messages:
    2,374
    Location:
    West coast
    find and download service manual, inspect schematic for any circuit breaker (rare) or fuses (common),
    and there may be one or two hidden like underneath, behind a shield, etc.

    then if you are experienced you can try tracing the power supply, assuming there is no indication
    of power (no lights, no hum when listening closely, no mechanical motion), and the eject button fails, etc
     
  3. CavScout

    CavScout Well-Known Member

    Messages:
    578
    100% without function.
    Before posting I searched online for a manual or schematic with no results :-(
     
  4. Bob

    Bob AK Subscriber Subscriber

    Messages:
    2,374
    Location:
    West coast
  5. CavScout

    CavScout Well-Known Member

    Messages:
    578
    Thanks for that:)
    I opened it up and still cannot find the fuse.
    Is it possible this thing in the photo is some sort of encapsulated fuse ?
     

    Attached Files:

  6. Bob

    Bob AK Subscriber Subscriber

    Messages:
    2,374
    Location:
    West coast
    look on the schematic and parts list (this is better since they will list parts by function))
    some fuses are encapsulated and do not look like the older car fuses with metal
    end-caps and glass cylindrical bodies.

    the schematic will verify the existence of a fuse usually as a "F" part with a number.

    lastly, some "IEC" style power connection may have a fuse inside the external
    portion, there is likely a label and/or stencil description for fuse or rated current.

    it may not be a fuse, but check the schematic for all power after the (usual) bridge
    rectifier. eg no other transformer tap nor off the primary side of the AC feed. if so
    and the power (and others) light is thus powered then the problem is either
    the power transformer or the bridge. the former may have an embedded
    fuse to protect that side of the winding. or the bridge supplying ALL power is
    blown and cannot light anything, preamp, lights, etc.

    if you post a pix of the power section we can go from there.
     

     

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  7. CavScout

    CavScout Well-Known Member

    Messages:
    578
    I only have those 2 docs from the download and nothing more.
    Everything else you mentioned went over my head (sorry I am a bit of a novice)
     
  8. CavScout

    CavScout Well-Known Member

    Messages:
    578
    I am pretty sure that black plastic thing in the photo has a fuse buried in it.
    If only I knew the amp rating I could splice a new one in there
     
  9. ryuuoh

    ryuuoh FFXIV Summoner Subscriber

    Messages:
    9,298
    Location:
    Marina CA, USA
    That fuse shown in the schematic might be internal to the transformer.
    edit
    If you have a multimeter, measure the suspected fuse for continuity.
     
  10. Bob

    Bob AK Subscriber Subscriber

    Messages:
    2,374
    Location:
    West coast
    the fuse is "AGC" plus there's an R73 between it and the transformer means it's external
    to the transformer and should be able to be found (easier to say this) by following the
    leads to/from AC and the transformer.

    to verify this, (that is no internal transformer fuse) is to google "617-..." (cannot see the
    other digits as O or 0) - the partnumber for the transformer).

    the fuse is 1/8A, and should be in a chassis-mounted fuse holder or an inline fuse
    holder that you twist and pull apart. you need to find this and verify it is bad before
    anything else like buying a new fuse.

    AGC is a physical fuse size and competes with the 5mm short fuses you see in many units.

    I also doubt the fuse is inside that black plastic thing, an AGC wouldn't fit and is not
    originally design-intended for this type of embedding; if for no other practical reason
    than the glass cylinder is intended to be used as a view into the fuse. the other side
    should be female AC prong sockets due to the wires hanging off it. and a fuse cannot
    be used across the AC lines. my opinion is that it is the "A" and "C" from the schematic.

    trace those wires - it will lead to the fuse. I now suspect, because there are no other power
    activated lights, that the fuse is your problem. now the issue is why it blew.
     
    Last edited: Dec 8, 2018 at 7:00 PM
  11. CavScout

    CavScout Well-Known Member

    Messages:
    578
    I have taken it apart completely and there is no fuse visible
     

     

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  12. Bob

    Bob AK Subscriber Subscriber

    Messages:
    2,374
    Location:
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    take several pictures of the area - pics that follow the wires from the black plastic plug to the
    transformer and to the AC supply.

    the fuse, blown, explains the power off condition. and the schematic shows a fuse and no other
    way any light is powered except through the bridge circuit that follows the transformer. therefore
    any power for the unit, including lights must come from the Power supply circuit that has
    fuse protection prior to the transformer.
     
  13. NAD80

    NAD80 Super Member

    Messages:
    2,286
    Location:
    Carlisle PA
    The fuse could be a PCB type fuse. 1/8 amp could be no larger than a 1/4W resistor. Pics of the interior could help.
     
  14. CavScout

    CavScout Well-Known Member

    Messages:
    578
    The schematics in that download must be wrong. None of the numbers match.
     
  15. CavScout

    CavScout Well-Known Member

    Messages:
    578
    Here are some pics
     

    Attached Files:

  16. Bob

    Bob AK Subscriber Subscriber

    Messages:
    2,374
    Location:
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    1. numbers don't match? pix2 shows about 10 opamps, and are they on the schematic?
    2. can't read parts stenciling on PCB from pix1 - maybe me.
    3. pix4 - good start, I see brown, blue wires (usually chosen for AC-side power)
    4. where is that black plastic thing in your earlier first pix in relationship to these pix?
    (I suspect the fuse will be attached at some point to the wires in this pix)

    I'd go back in and take close-up pix of the right side of the transformer in your pix4
    and work your way back to the AC feed into the CDP. what we're looking for is
    a fuse that may be hidden underneath something:
    a. its mounted on the chassis inside, on the back panel, or floating
    b. tracing these wires by hand and by pix will lead you back and
    either you find the fuse or as you say the schematic doesn't match the CDP

    I would hand trace each wire from the right side of the transformer all the way back
    to the AC inlet. pull up, gently, and take pix. closeup and crop (big battle between
    pixel count maximums and details when blown-up).

    is that schematic on the right side of pix4 pasted inside or your copy?

    do you have a VOM/DMM. you can verify the fuse is not in the transformer
    by measuring the resistance between the AC-side power wires (blue, brown
    and should only be the two) at the transformer, and if there's no available
    wire junction to do so, then move away and find the first.

    A fuse explains the problem, and the schematic shows one, and pictures
    and hand following the wires will prove it. However, if the schematic
    and/or the unit does not have a fuse, then it will take someone
    going in and tracing the live power to the point of failure.
     

     

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  17. CavScout

    CavScout Well-Known Member

    Messages:
    578
    I have had the entire unit taken apart and there is no glass fuse. There are also no fuses on the pc boards.
    The schematics are the wrong ones. Nothing matches.
    I am thinking that the black plastic thing has a fuse in it.
     
  18. Bob

    Bob AK Subscriber Subscriber

    Messages:
    2,374
    Location:
    West coast
    have you hand traced the wires? if so, and no fuse, then lets go back to your first
    picture and black plastic thing (BPT).

    if the other side does not have a female AC prong socket, then if that is directly
    wired from AC input to the transformer then yes, it might hold a fuse. take
    more pics of all sides of the BPT and post, there should be an opening for
    pulling the fuse.

    to ensure safety, take pix of where that BPT is mounted, it should not be free
    standing hidden somewhere. anyone sticking a finger in while live can get a
    nasty shot - there are bare joints on that BPT.
     
  19. CavScout

    CavScout Well-Known Member

    Messages:
    578
    I have already unfastened the BPT from the plastic frame it was mounted to.
    It is a fully sealed item. You can see where it was sealed at the factory so I am thinking of slicing it open or just creating a new fuse path
     
  20. Bob

    Bob AK Subscriber Subscriber

    Messages:
    2,374
    Location:
    West coast
    it is important that you
    1, trace the wires from the BPT and that it is in series with one (or the other) AC supply lines
    2. it is NOT in parallel or across the AC lines
    3. measure resistance of the BPT to verify there's an open (eg blown fuse)

    can I assume you hand-traced the wires as I suggested? I prefer to explain what
    I can see from pictures and not take a wild (for me) guess.

    that BPT from the first pix seems to have three or more wires. I would rather
    find out where they go before I assumed it contains a blown fuse.

    however, if all the questions and answers have been exhausted then what's
    left is the BPT being a fuse. but I would only go forward with pictures that
    confirm this.
     

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