Troubleshooting Help With Korg DS-8

Pulling out your hair? Don't know what to do or where to go? Ask in here.
Forum rules
READ: VSE Board-Wide Rules and Guidelines

If your Help request has been solved, please edit your first post in order to select the Image Topic Icon to let others know your topic has been solved.
Post Reply
User avatar
Audity
Newbie
Newbie
Posts: 23
Joined: Sun Jan 22, 2012 11:33 pm
Real name: Chris
Gear: Access Virus A, Waldorf Rocket, Alesis Micron, Yamaha DX7, etc. ...circuit bent and modded pieces
Band: (in progress!)
Location: Reno, NV

Troubleshooting Help With Korg DS-8

Post by Audity » Thu Nov 28, 2013 5:46 am

Hey all,
I picked up a Korg DS-8 at the thrift store the other day hoping it would be an easy fix. Long story short, it powers on with a blank screen and lit LEDs, but is otherwise completely unresponsive. No audio or MIDI either (although you can hear the "pop" of the op amps coming on when powering up) =/
It looked as though something sticky was spilled inside it many moons ago, most likely causing a short somewhere. I've been through the whole unit with a meter and scope, confirming that all the voicing circuitry, PSU and digital clocking all appear to be functioning. Unfortunately, I've got only a partial service manual and have diagnosed about as far as I can go.
I'm hoping somebody here may have some experience repairing these and may be able to shed some light on which IC(s) or components may be to blame for this synth failing to boot up. Any help or ideas would be appreciated! Thanks!!
REFERENCING THE PHOTO BELOW: SMD chip in the center is a proprietary Korg IC, and as such I'm assuming holds the Firmware and ROM memory. It outputs to the LED and LCD driver circuits. Traces get a little scattered going the other way, but most appear to go toward the large, through-hole IC and some of the chips around it. Can't find data sheets for most of these chips, so I'm not certain of most of their functions. All I can confirm is that they are recieving power, and most if not all are outputting signal of some sort (clock or waveform).

Image

User avatar
rhino
Supporting Member!
Supporting Member!
Posts: 2610
Joined: Sat Aug 02, 2008 5:00 pm
Real name: bill
Gear: keepers:
Kurzweil K2500x
Ensoniq TS-12
Yamaha SY-99
Alesis QS-8
Roland JD-800
Roland JX-10
Akai AX-80
Ensoniq SQ-80
Korg DSS-1
Moog Mini
Fizmo
Location: kentucky hills

Re: Troubleshooting Help With Korg DS-8

Post by rhino » Thu Nov 28, 2013 7:02 am

These may help:

http://ebookbrowsee.net/gdoc.php?id=260 ... 1ee90a424e

http://synthedoc.free.fr/Korg/Doc/korg_ ... part_2.pdf

You may want to remove the mainboard and wash it with hot water (yes!) or electronic cleaner. Coke and beer can realy reak havoc on pc boards.
When the wise man points to the stars, the fool looks at the finger.
- Confucius

Post Reply