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gosus
Joined: 05 Nov 2017 Posts: 12
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Posted: Mon Nov 27, 2017 10:49 am Post subject: Korg SV1 malfunction: freezes while playing! need help, pls |
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hi everyone!
my Korg SV1 freezes while i playing on it (with notes sounding enlessly, and no button responding). more notes played simultaneously - more chances it will freeze. more complicated the synthesis of a voice chosen - more chances for failure. After power off and on in works ok again, and then again gets stuck.
Here is the video: https://youtu.be/gKyeByDYdDc
it is running under OS v1.3 now (i have upgraded from v1.2, but the problem remains the same). I've opened it's case and checked all boards connections and wires - found nothing suspicious.
what else can i do to fix it?
many thanks |
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voip Platinum Member
Joined: 27 Nov 2014 Posts: 3773
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Posted: Mon Nov 27, 2017 9:23 pm Post subject: |
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Difficult to be sure of exactly where the problem lies but, since it seems to be polyphony-related, and the more complex the sound the sooner the problem arises, a possible cuplrit might be be the memory; either a fault in the memory itself, or in the memory address or data lines. As such, it will probably require the main board to be replaced, which is unfortunately not cheap; $880.50 from:
https://www.guitar-parts.com/catalog/korg-sv173-sv188-main-board-gra0002143
Replacing the memory devices is an option, but there's no guarantee of success, so a bit of a gamble, but certainly a lot cheaper than a new main board.
The chips are: K4S641632K-UC75 for the effects SDRAM and V54C3256164VDI7PC for the main processor SDRAM. |
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gosus
Joined: 05 Nov 2017 Posts: 12
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Posted: Tue Nov 28, 2017 9:55 am Post subject: |
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Thank you for information!
Of course, i'll try to replace memory.
How many chips do i need?
Where can i buy them?
thank you so much! |
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voip Platinum Member
Joined: 27 Nov 2014 Posts: 3773
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Posted: Tue Nov 28, 2017 7:25 pm Post subject: |
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One of each memory device type is fitted to the SV-1 main board.
As for sourcing the parts, use a search engine, and/or go to sites like Mouser, or Digikey, or Farnell, or the bay of thieves. The decision on where to buy from may be influenced by your location.
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gosus
Joined: 05 Nov 2017 Posts: 12
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Posted: Thu Nov 30, 2017 5:08 pm Post subject: |
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voip wrote: |
The chips are: K4S641632K-UC75 for the effects SDRAM and V54C3256164VDI7PC for the main processor SDRAM. |
i am very sorry, but where did you find V54C3256164VDI7PC?
i am reading the service manual right now and see
"SDRAM 64MB 16B K4S641632K-UC75
SDRAM256Mb MT48LC16M16A2P-75:D" |
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voip Platinum Member
Joined: 27 Nov 2014 Posts: 3773
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Posted: Thu Nov 30, 2017 10:12 pm Post subject: |
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Hmm, yes, it seems the schematic gives V54C3256164VDI7PC for the 256MB SDRAM and the parts list shows the SDRAM part as: MT48LC16M16A2P-75:D.
May I suggest looking at the part actually fitted to the mainboard to get the definitive answer. |
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gosus
Joined: 05 Nov 2017 Posts: 12
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Posted: Sat Dec 02, 2017 9:34 am Post subject: |
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voip wrote: | May I suggest looking at the part actually fitted to the mainboard to get the definitive answer. |
thanks, will go this way. |
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gosus
Joined: 05 Nov 2017 Posts: 12
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Posted: Thu Apr 05, 2018 3:52 am Post subject: |
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voip wrote: | Hmm, yes, it seems the schematic gives V54C3256164VDI7PC for the 256MB SDRAM and the parts list shows the SDRAM part as: MT48LC16M16A2P-75:D.
May I suggest looking at the part actually fitted to the mainboard to get the definitive answer. |
Both memory modules replacement made a fix!
my SV1 works perfectly!
thanks a lot! |
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gosus
Joined: 05 Nov 2017 Posts: 12
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Posted: Mon Sep 10, 2018 9:27 pm Post subject: |
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hi!
will sell motherboard for $400
onanko@mail.ru |
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