Korg Forums Forum Index Korg Forums
A forum for Korg product users and musicians around the world.
Moderated Independently.
Owned by Irish Acts Recording Studio & hosted by KORG USA
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Korg SV1 malfunction: freezes while playing! need help, pls

 
Post new topic   Reply to topic    Korg Forums Forum Index -> Korg SV-1
View previous topic :: View next topic  
Author Message
gosus



Joined: 05 Nov 2017
Posts: 6

PostPosted: Mon Nov 27, 2017 10:49 am    Post subject: Korg SV1 malfunction: freezes while playing! need help, pls Reply with quote

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
Back to top
View user's profile Send private message
voip
Platinum Member


Joined: 27 Nov 2014
Posts: 1164

PostPosted: Mon Nov 27, 2017 9:23 pm    Post subject: Reply with quote

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.
Back to top
View user's profile Send private message
gosus



Joined: 05 Nov 2017
Posts: 6

PostPosted: Tue Nov 28, 2017 9:55 am    Post subject: Reply with quote

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!
Back to top
View user's profile Send private message
voip
Platinum Member


Joined: 27 Nov 2014
Posts: 1164

PostPosted: Tue Nov 28, 2017 7:25 pm    Post subject: Reply with quote

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.

.
Back to top
View user's profile Send private message
gosus



Joined: 05 Nov 2017
Posts: 6

PostPosted: Thu Nov 30, 2017 5:08 pm    Post subject: Reply with quote

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"
Back to top
View user's profile Send private message
voip
Platinum Member


Joined: 27 Nov 2014
Posts: 1164

PostPosted: Thu Nov 30, 2017 10:12 pm    Post subject: Reply with quote

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.
Back to top
View user's profile Send private message
gosus



Joined: 05 Nov 2017
Posts: 6

PostPosted: Sat Dec 02, 2017 9:34 am    Post subject: Reply with quote

voip wrote:
May I suggest looking at the part actually fitted to the mainboard to get the definitive answer.


thanks, will go this way.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    Korg Forums Forum Index -> Korg SV-1 All times are GMT
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group