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M50 Capacitor Trouble

 
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cano19781



Joined: 11 Sep 2014
Posts: 3
Location: Caracas

PostPosted: Thu Sep 11, 2014 9:30 pm    Post subject: M50 Capacitor Trouble Reply with quote

I'm from Venezula, and We don't have any korg services here, by the way, my Korg M50 doesn't work very well, you know a very famous capacitor trouble, I have a very good friend of mine, and he is an electronical engeneer, I would like to know which specific capacitor we need to replace because we try to fix my keyboard, please somebody help us.
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remixcero



Joined: 01 Mar 2010
Posts: 8
Location: Maxico Guadalajara

PostPosted: Mon Oct 20, 2014 3:34 am    Post subject: problem nothing response, the display when its frozen M50 Reply with quote

the problem begin when
can't comunicate with host CPU correctly. this the direct cause of these problem. this would happen when the power regulators output has large ripple voltaje, at 1.8v power regulator on KLM 2887. this ripple voltaje could be large because ot the parts tolerance of this power regulator circuit.
this system version controls drive power down at CPU ports, it makes total power consumption of CPU down. as the result these problems should be fixed in most cases according to our test.

however, rarely, when ripple voltage is very large because of range of parts tolerance in this regulator circuit, v 1.0.5 or later, cant solve the problem, in this case, it requires to remplace the capacitor C153, C37 (tantal capacitor)




Spanish

el problema comienza cuando
no se puede comunicar con la CPU del host correctamente. esta la causa directa de estos problemas. esto iba a pasar cuando la salida de los reguladores de energía tiene gran Voltaje ondulación, en el regulador de energía 1.8v con KLM 2887. esta Voltaje de rizado puede ser grande porque ot la tolerancia partes de este circuito regulador de potencia.
este sistema de control de versión en coche apagado en los puertos de la CPU, que hace que el consumo total de energía de la CPU hacia abajo. como resultado de estos problemas deben fijarse en la mayoría de los casos de acuerdo a nuestra prueba.

Sin embargo, rara vez, cuando el voltaje de ondulación es muy grande debido a la gama de tolerancia partes en este circuito regulador, v 1.0.5 o posterior, no puedo resolver el problema, en este caso, que se requiere para REMPLACE el condensador C153, C37 (condensador de tantalio)
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pablolec



Joined: 19 May 2015
Posts: 1
Location: Argentina

PostPosted: Tue May 19, 2015 6:51 pm    Post subject: Reply with quote

hola, soy de Argentina y tengo el mismo problema, que se cuelga toda funcion en el KORG M50 y tengo que reiniciarlo. Me queda claro que son 2 los capacitores a cambiar, pero en que lugar? me han dicho que en la fuente de alimentacion y otros dentro del teclado. Por favor ayudenme, esto me esta volviendo loco!
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yarasa



Joined: 27 Aug 2015
Posts: 1

PostPosted: Thu Aug 27, 2015 10:01 pm    Post subject: Reply with quote

If the capacitors are electrolytic, check if they bulged out. You can desolder it and replace it with the same one; the same value and voltage rating. If the capacitors are surface mounted check the connections of the terminals to the board. The connections may have detached due to some vibrations or mishandling of the unit. To fix this you could reheat the solders and have the solder reflow.
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michelkeijzers
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Joined: 08 Feb 2007
Posts: 9113
Location: Netherlands

PostPosted: Fri Sep 09, 2016 10:03 pm    Post subject: Reply with quote

I seem to have the same problem. My 3 scenarios when I switch it on:
- Screen showing 'updating left panel, updating right panel, please switch off synth'
- No buttons and joystick work, but all keys does (so I cannot change from program I-A000)
- Everything works but for some seconds, than the previous scenario shows up

I tried to reconnect most cables but without any improvement.
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viya0414



Joined: 24 Aug 2017
Posts: 1

PostPosted: Thu Aug 24, 2017 3:26 am    Post subject: Reply with quote

If the capacitors are surface mounted check the connections of the terminals to the board.

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roc1



Joined: 26 Dec 2018
Posts: 3

PostPosted: Wed Dec 26, 2018 7:50 am    Post subject: Reply with quote

I can attest, remixcero's solution works. Here is what I did:

1. I soldered a second low resistance tantalum 100 uF SMD cap in parallel to the existing C37 (didn't take the existing one out). My keyboard is a different board revision and it doesn't have C153.

2. Cleaned up the gobs of flux residue on the PCB and remelted all contacts covered by the flux. Leftover flux corrodes solder joints!

One of these fixed it.

Cross-posting in this thread which is on the same topic.
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Alp
Full Member


Joined: 09 Jan 2010
Posts: 137

PostPosted: Fri Feb 01, 2019 1:12 am    Post subject: Reply with quote

I have images of the two capacitors. They are on the opposite sides of the same board.

I replaced the original capacitors with regular electrolytic. I THINK they were originally Tantalum. The keyboard worked well for a number of years but now I am having some issues.

[img]E:\text\korg\korg cap 1.jpg/[/img]
[img]E:\text\korg\korg cap 2.jpg/[/img]


Last edited by Alp on Fri Feb 01, 2019 1:21 am; edited 1 time in total
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Alp
Full Member


Joined: 09 Jan 2010
Posts: 137

PostPosted: Fri Feb 01, 2019 1:13 am    Post subject: Reply with quote

OK, so how do I insert images from hard drive into post?
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voip
Platinum Member


Joined: 27 Nov 2014
Posts: 3758

PostPosted: Fri Feb 01, 2019 8:55 pm    Post subject: Reply with quote

Korgforums doesn't store any images. In order to get images into a posting, upload the files to a hosting website, then link to them in the message.

For example, the schematic a few postings above this one, is actually at:

http://sia1.subirimagenes.net/img/2014/10/20/141020084211552396.png

I tend to use an adblocker to prevent images from coming up, since they can sometimes be intrusive. A link might be preferable.
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Bobcat22
Junior Member


Joined: 12 Nov 2018
Posts: 74

PostPosted: Tue Feb 19, 2019 7:19 am    Post subject: Now Blank Screen Reply with quote

Prior to the existing problem, I replaced the 2 capacitors. The unit would freeze. Then the screen is just white/blank. This M-50 was hardly used and looks new.

bc
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manish trivedi



Joined: 09 Jan 2020
Posts: 1
Location: india

PostPosted: Thu Jan 09, 2020 11:26 am    Post subject: Reply with quote

Alp wrote:
I have images of the two capacitors. They are on the opposite sides of the same board.

I replaced the original capacitors with regular electrolytic. I THINK they were originally Tantalum. The keyboard worked well for a number of years but now I am having some issues.

[img]E:\text\korg\korg cap 1.jpg/[/img]
[img]E:\text\korg\korg cap 2.jpg/[/img]

Not showing pic
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Bobcat22
Junior Member


Joined: 12 Nov 2018
Posts: 74

PostPosted: Thu Jan 09, 2020 5:20 pm    Post subject: Reply with quote

You are posting images which do not show, did you not review your post before you left?
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