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<DIV>If you envision doing much of this you might consider looking for a used
Sencore LC102 or LC103 to check caps one at a time.</DIV>
<DIV>This way you will be sure about the caps without just replacing them
all. Much better than an ESR meter.</DIV>
<DIV> </DIV>
<DIV>Barry</DIV>
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<DIV style="font-color: black"><B>From:</B> <A title=mtaylor.tech@gmail.com
href="mailto:mtaylor.tech@gmail.com">Michael Taylor</A> </DIV>
<DIV><B>Sent:</B> Sunday, August 28, 2016 4:40 PM</DIV>
<DIV><B>To:</B> <A title=analogue@hyperreal.org
href="mailto:analogue@hyperreal.org">Analogue Heaven AH</A> ; <A
title=synth-diy@dropmix.xs4all.nl
href="mailto:synth-diy@dropmix.xs4all.nl">synth-diy@dropmix.xs4all.nl</A> </DIV>
<DIV><B>Subject:</B> [sdiy] Does anybody have a BOM for the MPC3000 power PCB
and powerfilter PCB?</DIV></DIV></DIV>
<DIV> </DIV></DIV>
<DIV
style='FONT-SIZE: small; TEXT-DECORATION: none; FONT-FAMILY: "Calibri"; FONT-WEIGHT: normal; COLOR: #000000; FONT-STYLE: normal; DISPLAY: inline'>Hey
all,
<DIV> </DIV>I've decided that it's finally time to recap the power supply
on this MPC3000 due to weird ground noise issues.
<DIV> </DIV>
<DIV>The MPC is very quiet when not in use, or when playing back preexisting
samples. When you put it into sampling mode it is quiet until you plug in a
cable and then it has a very loud high pitched buzz. The cable does not have to
be connected to anything, just the act of plugging in a cable starts the MPC
buzzing. Pull the cable out and it's quiet again.</DIV>
<DIV> </DIV>
<DIV>-This has happened in my studio and at the workshop at my job(separate
buildings about 1.5 miles apart).</DIV>
<DIV> </DIV>
<DIV>-This is not transformer buzz or a whine from the inverter(the transformer
is physically silent and the inverter is a separate sound that stops when I shut
off the LCD backlight).</DIV>
<DIV> </DIV>
<DIV>-This issue has arisen in the last six months, it was relatively quiet
before that. </DIV>
<DIV> </DIV>
<DIV>-This happens with no other connections that a 1/4" cable and the
headphones or stereo outs to a mixer(IOW SCSI is not part of the picture and
this happens with or with a SCSI drive connected).</DIV>
<DIV> </DIV>
<DIV>-This sound is present in all new samples that are recorded while there is
a high pitched buzz. You can sample silence, and the MPC will be silent in
playback mode and then you will hear the buzz when you play the sample and then
silence after the sample stops. </DIV>
<DIV> </DIV>
<DIV>-The MPC sequences midi, accesses a SCSI CF drive, and plays back samples
completely normally outside of the sampling issue. </DIV>
<DIV> </DIV>
<DIV>So my two questions are:</DIV>
<DIV> </DIV>Can you guys think of anything else I can do to trouble shoot
this issue besides redoing the PS boards?
<DIV> </DIV>
<DIV>Does anybody have a preexisting BOM for the caps on these PCB? </DIV>
<DIV> </DIV>
<DIV>I have the service manual, but the parts listings are cryptic for some
parts and completely missing for others. </DIV>
<DIV> </DIV>
<DIV>Thanks,</DIV>
<DIV>Mike</DIV>
<DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV> </DIV></DIV>
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