1. Time for some upgrades in server hardware and software to enhance security and take AK to the next level. Please contribute what you can to sales@audiokarma.org at PayPal.com - Thanks from the AK Team
    Dismiss Notice

Marantz 250M Power Amp Service Bulletins

Discussion in 'Marantz Audio' started by Pete B, Nov 6, 2018.

  1. Pete B

    Pete B AK Member Subscriber

    Messages:
    1,965
    Location:
    CT, USA
    I found Service Bulletins (SB) 2-5 for the 250M not the 250 in the digital database Marantz (page 10)
    section of AK, they are free for download: http://akdatabase.com/AKview/index.php
    M-250-2 Mar 26, 1975 New part numbers for specific transistors and rules for beta selection
    M-250-3 Aug 16, 1976 Increased reliability by replacing pre, driver, and output transistors.
    Add flyback diodes, bias and test unit.
    M-250-4 Sept 24, 1976 Correction to bias setting in M-250-3, sets current to 1/2 of previous.
    M-250-5 Nov 15, 1977 New part number for power transformer and how to replace a failed one.

    The 250 manuals can also be found there but much earlier in the database.

    Anyone have SB M-250-1 ?
     

     

    Please register to disable this ad.

  2. angusdog

    angusdog AK Subscriber Subscriber

    Messages:
    24
    Hey Pete.I see you are here also.
     
  3. rickl

    rickl Active Member

    Messages:
    109
    Location:
    Twin Cities
    Pete, I have form No. 199-1074. Not sure if this is what you are looking for or this is something listed above.
     

    Attached Files:

Share This Page