Marantz Model 4300 needs help

Discussion in 'Marantz Audio' started by AsRock, Apr 27, 2018.

  1. EastPoint

    EastPoint Factory Code No. 4200 Subscriber

    Messages:
    4,412
    Location:
    Milwaukee, WI
    KSC1845. Ideally all 2SC458s should be replaced but wait until this is working.
     
    AsRock likes this.

     

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  2. AsRock

    AsRock New Member

    Messages:
    37
    Location:
    Pittsburgh
    Thanks all, and @catrafter (PMs)

    Have only the working module in. I am now getting sound though the right channels ( Main Front \ Remote Front ), the other module was coursing a short at the relays stopping all from working before.

    Getting stereo though the front headphone socket still and nothing though the rear headphone socket,

    Compered both P700 boards and finding nothing else majorly different, there are 6 transistors that show as a short on each while in circuit so to be sure i removed them all and tested each one and found no shorts.

    KSC1845 has a 13 week lead time so nothings going be added until at least that time lol.

    Was thinking of checking the slot the cards plug into as well see if the voltages and such are the same too.

    Did i miss some thing ?.

    There is some thing i need and that's the 4 screws that hold the card slots in place, the ones i have barely do it and do not hold up at all. I thought i had found some good replacement's ( same thread ) but were to long.

    Looked in the SM and they are 1822 and says they are B.H.M screws no size of any kind. I think i will just go the hardware store and take one of the screws that did fit, and they fit really well.
     
  3. EastPoint

    EastPoint Factory Code No. 4200 Subscriber

    Messages:
    4,412
    Location:
    Milwaukee, WI
    If mouser is out of KSC1845s, check eBay.
     
  4. AsRock

    AsRock New Member

    Messages:
    37
    Location:
    Pittsburgh
    Put a back order in for 100,. i can wait.
     
  5. AsRock

    AsRock New Member

    Messages:
    37
    Location:
    Pittsburgh
    OOh look what i got early, figures though as i put it away then these pop up :). Just after some fire resistant 1/2w 100Ohm resistors now.

    As just buying a few resistors it's going cost like $5 so was thinking of replacing the caps on the power board (P800), and wanted to know which i should pick for the unit.

    [​IMG]
     
  6. AsRock

    AsRock New Member

    Messages:
    37
    Location:
    Pittsburgh
    Well went though 80\100 of them listed the hfe \ Vbe \ IB and the gains much lower so i am asking is this going be a issue for any other part of the boards.

    The one original that is working has hfe of 97 now the replacements have at least a hfe of 371

    Old
    hfe 97 \ VBE 0.766 \ Is 4.194

    Best match i can find

    370 \ 0.741 \ 4.217
    371 \ 0.741 \ 4.217

    Question, should the 4 pots on the board be changed as 2 of the main transistors have been replaced ( anticlockwise minimum ? )

    Thanks.
     

     

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