[Search for users] [Overall Top Noters] [List of all Conferences] [Download this site]

Conference 7.286::atarist

Title:Atari ST, TT, & Falcon
Notice:Please read note 1.0 and its replies before posting!
Moderator:FUNYET::ANDERSON
Created:Mon Apr 04 1988
Last Modified:Tue May 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:1433
Total number of notes:10312

1122.0. "power supply died c2331 = ?" by EVTAI1::LEGER (Vous avez dit GRAPHIQUE ?) Tue May 14 1991 12:10

    
    My 1040STF power supply died !
    I found Q1 and Q2 in short circuit.
    No problem to replace Q2 (BU 508 A)
    but i do not find Q1 (C 2331) !
    Does anybody know its characteristic or an equivalent ?
    Thanks
    					Jean-Claude.
    
T.RTitleUserPersonal
Name
DateLines
1122.1C2331 probably = 2SC2331GIDDAY::HIRSHMANGIGO: Garbage In, Gospel OutWed May 15 1991 01:155
    If it's a Japanese made transistor then the real type number is
    2SC2331.  Japanese manufacturers always omit the "2S" prefix when they
    stamp ID's on their semiconductors.
    
    Sorry, but I don't have any specs for the 2SC2331.
1122.2Replacement part numberMPGS::RADOFFWed May 15 1991 13:0013
    If the part is indeed a 2SC2331, then Motorola has a similar
    replacement MJE13004.  This is a high voltage switching power supply
    switching transistor.
    
    More importantly, why did these transistors blow out.  Did the fuse
    blow out?  Is there a short in the power transformer?  Did a secondary
    circuit rectifier or capacitor fail?  Did a primary side component
    fail?  Did a feedback component fail?  What I am suggesting is that
    failure of the main switching transistors may not be remedied simply by
    replacing the parts.  The problem may be more serious than that.  These
    power supplies tend to be very reliable.
             
    	Steve
1122.3Thanks, and ...EVTAI1::LEGERVous avez dit GRAPHIQUE ?Thu May 16 1991 05:0411
    
    Thanks ,
    You're right ,why did these transistors blow out ?
    I don't know ... the fuse blow out , but not after removing these
    transistors .Rectifier are ok ,and capacitor aren't in short circuit.
    I don't know how to test transformer.
    The ST in running correctly with 2 external power supplies 
    I will recheck every transistor,rectifier and capacitor before power up
    the suply with load resistor.
    
    					Jean-Claude. 
1122.4Replacements are availablePRNSYS::LOMICKAJJeffrey A. LomickaThu May 16 1991 12:252
By the time you put in all that effort, you could have bought a
replacement from Best Electronics.  They are very proud of it.
1122.5Its more satisfying to D.I.Y.UKCSSE::KEANEFri May 17 1991 05:0713
    
    Hi,
    
    Jeff...... Jean Claude will be even more proud than Best, at being able
    to fix his power supply himself!
    
    Re the power transistor failure. I have an old Sony C7 VCR that uses
    these transistors. They blew on that, for no apparent reason. I
    replaced them only, (after checking everything else) and the power
    supply came up and ran OK!  
    
    Pat K.