Sean,

A few things I will recommend.

1. since on power on you have delay and relay it sounds to me
   that relay works as a mute to cut the power on pop sound
   take the relay cover out and spray WD40 in it.

2. press and hold a note and with any thing gently click on relay see
   if the sound cuts out if it is then it is relay problem.

3. press and hold a note and with none conductor pen or something
   tap on whole board see if the sound cuts out if it is happening
   in relay area then it is relay contact problem or loose connection.

4. use line out connector left and right connect it to other amp
   for test if it does the same thing then internal amp is ok if
   it sounds fine then your problem is in the amp section.


Andre Abelian




-----Original Message-----

Hi all,

Sorry for the way-OT mail. I've looked all over for info on this and
have
not been able to find it, even on the relevant newsgroups. I once again
approach the amazing piclist for help from its vast store of knowledge
;-)

I have a friend who has a Korg C-505 Digital Piano. A couple of weeks
ago,
it started occasionally shutting off while he was playing it. It has
since
gotten worse. It does not matter whether you are manually playing or
playing a tune from its internal memory, but it does seem more likely to
quit when notes are actually being played as opposed to sitting idle.
When
it is on, it seems to work fine.

When you turn it on, there is a brief period of about 3 seconds before
it
can be played. After this brief delay, you hear a relay click and then
it
is ready to play. It has always done this. When it quits, you hear the
same
relay click sound, and sometimes the power LED remains on, sometimes it
doesn't.

He asked me to take a look at it. We opened it up and I looked over both
the digital board and the amp/power supply board for anything obviously
wrong and I couldn't find anything. No burnt components or anything
similar.

Since these things run a good $1000 and the only shop in our town that
fixes them is run by a couple of idiots (from what I hear), I'd like to
have a go at fixing this for him. We looked around the net for a service
manual, schematic, or other info and found nothing for this particular
Korg
model, probably because they now focus on synths.

Finally the question: does anyone here know of a source for additional
info
on this machine or know someone who is familiar with it and might be
able
to suggest some things for me to check?

Thanks,

Sean

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