Anyone has a schematic or service manual for any DSW-Micropro subs?

Been a long time fan and never really had much issues with any of my Polk Audio speakers and subs until recently. My MPK1000 just burned 4 of the 6 bigger resistor in the amp board, preamp section and power supply are still good, my MPK2000 keeps blowing fuse on the power supply and burned the 2 variable resistors in the amp section. My MPK4000 still works good however it now has a hum and whenever I turn it on and off there will always be a mild pop and a second louder pop. I can repair stuff but will need a schematic, does anyone here know where can I get one?

Comments

  • SeleniumFalcon
    SeleniumFalcon Posts: 3,452
    I'll ask a friend at Polk for information.
  • rooftop59
    rooftop59 Posts: 7,952
    rob824 wrote: »
    Been a long time fan and never really had much issues with any of my Polk Audio speakers and subs until recently. My MPK1000 just burned 4 of the 6 bigger resistor in the amp board, preamp section and power supply are still good, my MPK2000 keeps blowing fuse on the power supply and burned the 2 variable resistors in the amp section. My MPK4000 still works good however it now has a hum and whenever I turn it on and off there will always be a mild pop and a second louder pop. I can repair stuff but will need a schematic, does anyone here know where can I get one?

    That’s unfortunate. By all accounts those were polks best performing (and most expensive!) subs ever. However, it seems the company absolutely cannot be trusted to make any powered gear that will function properly and actually last…
    Living Room 2.2: Usher BE-718 "tiny dancers"; Dual DIY Dayton audio RSS210HF-4 Subs with Dayton SPA-250 amps; Arcam SA30; Musical Fidelity A308; Sony UBP-x1000es; Squeezebox Touch with Bolder Power Supply
    Game Room 5.1.4:
    Denon AVR-X4200w; Sony UBP-x700; Definitive Technology Power Monitor 900 mains, CLR-3000 center, StudioMonitor 350 surrounds, ProMonitor 800 atmos x4; Sub - Monoprice Monolith 15in THX Ultra

    Bedroom 2.1
    Cambridge Azur 551r; Polk RT25i; ACI Titan Subwoofer
  • SeleniumFalcon
    SeleniumFalcon Posts: 3,452
    Schematic sent.
  • rob824
    rob824 Posts: 8
    The DSW-Micropro 1000 and 2000 actually lasted for more than 10 years of use for watching movies, took good care of it and volume level is always at 30/40 and levels on the receiver is set to 0, room correction is always set to corner. I have switched outlets so these subs are never left on standby. My Micropro 4000 is used for music in my separate room combined with a pair of RTi A7 still works but pops twice whenever it gets turned on and off. I know I already got my moneys worth on them but I want to prolong their life as as they don’t get any better in Polks line of subs.

    For anyones curiosity I attached a snapshot of both the DSW-Micropro 1000 and 2000 amp board.e5jn7srwg7sk.jpeg
    9dxq8kxcwjnm.jpeg
  • txcoastal1
    txcoastal1 Posts: 13,124
    When you review the schematic I am curious of what's going on what i marked on the board with yellow box.y727byora31a.jpeg
    2-channel: Modwright KWI-200 Integrated, Dynaudio C1-II Signatures
    Desktop rig: LSi7, Polk 110sub, Dayens Ampino amp, W4S DAC/pre, Sonos, JRiver
    Gear on standby: Melody 101 tube pre, Unison Research Simply Italy Integrated
    Gone to new homes: (Matt Polk's)Threshold Stasis SA12e monoblocks, Pass XA30.5 amp, Usher MD2 speakers, Dynaudio C4 platinum speakers, Modwright LS100 (voltz), Simaudio 780D DAC

    erat interfectorem cesar et **** dictatorem dicere a
  • rob824
    rob824 Posts: 8
    Those are 2 Thyristors that were glued to the backplate they measure a good 250 and 229 ohms.
  • rob824
    rob824 Posts: 8
    SF, could not find the schematic anywhere 😅
  • txcoastal1
    txcoastal1 Posts: 13,124
    rob824 wrote: »
    Those are 2 Thyristors that were glued to the backplate they measure a good 250 and 229 ohms.

    Is there one missing?
    2-channel: Modwright KWI-200 Integrated, Dynaudio C1-II Signatures
    Desktop rig: LSi7, Polk 110sub, Dayens Ampino amp, W4S DAC/pre, Sonos, JRiver
    Gear on standby: Melody 101 tube pre, Unison Research Simply Italy Integrated
    Gone to new homes: (Matt Polk's)Threshold Stasis SA12e monoblocks, Pass XA30.5 amp, Usher MD2 speakers, Dynaudio C4 platinum speakers, Modwright LS100 (voltz), Simaudio 780D DAC

    erat interfectorem cesar et **** dictatorem dicere a
  • rob824
    rob824 Posts: 8
    TX, thyristors are there, values I gave are from my multimeter they were just soldered at the back of the pcb boarddtmlmda04dlc.jpg.

    I am still awaiting for the schematics, it might have just been stuck somewhere you know how internet traffic is, never instant. I just pulled the 4 big resistor and there is 1 small badly burnt one.
  • pitdogg2
    pitdogg2 Posts: 24,477
    pyxdgcnfocb8.jpg

    Is that in red good? Looks (from my perspective) like it got hot.
  • rob824
    rob824 Posts: 8
    All the diodes checked out good that is just probably my lighting, just can’t figure the real value of those 4 identical resistors in the middle, from what I see is black brown black a 1 ohm resistor plus minus 20% since it does not have a 4th band just looking at it it’s very odd. checked it with my multimeter and I don’t get any reading same in my LCR meter as t cannot be identified. Hopefully anyone can help me!
  • SeleniumFalcon
    SeleniumFalcon Posts: 3,452
    Are you lifting one of the resistor's leads from the circuit board before measuring the resistance?
  • rob824
    rob824 Posts: 8
    Are you lifting one of the resistor's leads from the circuit board before measuring the resistance?

    Yes, that is what I did first before even deciding to pull them out of the board. no reading in diode mode, and no reading when multimeter is set in resistance mode both at 200 and 2k.
  • SeleniumFalcon
    SeleniumFalcon Posts: 3,452
    I guess they're open. What is the part number?
  • rob824
    rob824 Posts: 8
    Schematic sent.

    U D Man Sir, thank you very much for the help! :smiley:

  • I have a dsw micropro 1000 too that suddenly completely stopped working - no lights nothing, fuse ok and power getting in. before I poke around components can someone please share a schematic?
  • Hello,
    Welcome, I'll ask.
  • Email with schematic sent.