VOGONS


Korg NS5R Service Manual

Topic actions

First post, by Jackhead

User metadata
Rank Member
Rank
Member

Hi,

i need to do some repair on a Korg NS5R voltage regulator and looking for the Service Manual / Schematics. Can someone help me out with it?
Searching on the net dont show up anything.

regards
Chris

Dos 6.22: Asus VL/I-486SV2GX4 Rev 2.0 1Mb L2 - A5x86 X5 P75 - 64MB RAM - Promise EIDE2300+ - ET4000W32P VLB - CT2230 - GUS ACE - MPU-401AT
Win98SE: Asus P5K-WS - E8600 @ 4,5GHz - Strange God Voodoo 5 6000 PCI @ 66MHz PCI-X - 2GB DDR2 1066 - Audigy 2 ZS

Reply 1 of 7, by Jackhead

User metadata
Rank Member
Rank
Member

I opened the unit and i think i see whats wrong. There are 2 blown resistors near the PSU plug on the board.
So this will be a easy fix when i know what parts i need. Anyone can help?

The attachment IMG_0104.JPG is no longer available

Dos 6.22: Asus VL/I-486SV2GX4 Rev 2.0 1Mb L2 - A5x86 X5 P75 - 64MB RAM - Promise EIDE2300+ - ET4000W32P VLB - CT2230 - GUS ACE - MPU-401AT
Win98SE: Asus P5K-WS - E8600 @ 4,5GHz - Strange God Voodoo 5 6000 PCI @ 66MHz PCI-X - 2GB DDR2 1066 - Audigy 2 ZS

Reply 2 of 7, by Jackhead

User metadata
Rank Member
Rank
Member

So i contact KORG support and they are so kind to give me the service manual with the shematics.
I found it in the shematics but i dont know what they are??? They not in the parts list.
I need C121, C124, C129, C130 they look all the same typ with CE 3216.
Did anyone can tell me what they are?

The attachment IMG_0125.JPG is no longer available

Dos 6.22: Asus VL/I-486SV2GX4 Rev 2.0 1Mb L2 - A5x86 X5 P75 - 64MB RAM - Promise EIDE2300+ - ET4000W32P VLB - CT2230 - GUS ACE - MPU-401AT
Win98SE: Asus P5K-WS - E8600 @ 4,5GHz - Strange God Voodoo 5 6000 PCI @ 66MHz PCI-X - 2GB DDR2 1066 - Audigy 2 ZS

Reply 3 of 7, by koitsu

User metadata
Rank Newbie
Rank
Newbie

That's funny, I just contacted Korg to ask for schematics or troubleshooting advice.
Is there any chance you could send me the service manual?

I've got an NX5R with an intermittent boot issue. Since it mostly happens only during warm start, I suspect a capacitor but it's apparently possible that heat cycling could have compromised the solder joints in other components near the PSU. I came across an instance of an NS5R where the crystal near the filter caps apparently detached from the board. Trying to investigate as much as possible before taking the shotgun approach of a full recap...!

And have you had any luck with your NS5R?

Reply 4 of 7, by koitsu

User metadata
Rank Newbie
Rank
Newbie

By the way, sorry, didn't answer your question.
The parts labeled Cxxx are capacitors. If there is a parts list elsewhere in the manual... [EDIT: linked in post below]

Last edited by koitsu on 2020-10-26, 19:59. Edited 1 time in total.

Reply 6 of 7, by pentiumspeed

User metadata
Rank l33t
Rank
l33t

Use 50V SMD capacitor around 20nF or so they are not for smoothing, is for suppressing noise hence value is small.

Cheers,

Great Northern aka Canada.

Reply 7 of 7, by aspiringnobody

User metadata
Rank Member
Rank
Member
pentiumspeed wrote on 2020-10-24, 19:02:

Use 50V SMD capacitor around 20nF or so they are not for smoothing, is for suppressing noise hence value is small.

Cheers,

FYI for posterity -- My NS5R just let the smoke out -- I thought it was the transformer but ended up being one of these caps. They're tantalum. I measured them with my fluke when I took out the three "good" ones and they were all 130nF caps. I replaced them with .1 uF ceramic caps because -- that's what I had handy. When this blew it COMPLETELY destroyed the traces on the top side of the board.. no chance of fixing. I ended up having to use through-hole caps and scratch away the solder mask around the connector on the bottom of the board, bridging the cap between the pins from the transformer to the ground plane.

STRONGLY recommend replacing these BEFORE they blow. 15 minute fix if you catch it before it melts the traces. It didn't blow the fuse in my unit -- just kept smoking until I got to the plug to kill it. Also, it melted down after I turned it off (no sign of issue for the ~2 hours I was using it while playing a game) -- I think the switch might not be until after the rectifier (e.g. the transformer is always hot). So maybe keep it unplugged when not in use?

- Evan