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 

R3 tempo knob solution

 
Post new topic   Reply to topic    Korg Forums Forum Index -> Korg RADIAS / R3
View previous topic :: View next topic  
Author Message
hugoguti



Joined: 23 Oct 2011
Posts: 2

PostPosted: Tue Oct 25, 2011 5:22 pm    Post subject: R3 tempo knob solution Reply with quote

Hello everybody, I want to contribute to this problem with a solution. Two days ago a classmate ask me to fix his R3 and at that moment I had thought it was just the pot so I replaced it but the problem persisted. A quick search brought me to http://www.korgforums.com/forum/phpBB2/viewtopic.php?t=38899 so I tried with the 1000pF capacitor and the problem is fixed now. I will explain the way to fix it. Why am I doing this? Because thank to the people who do that I've learned a lot, so I wanna give something back.
Before the steps the typical warning. DO THIS ONLY IF YOU HAVE BASIC ELECTRONIC KNOWLEDGE, MEDIUM SOLDERING SKILLS AND A MULTIMETER. DO THIS AT YOUR OWN RISK. MAYBE THERE ARE DIFFERENT PCB VERSIONS, CAREFULLY FOLLOW THE RECOMENDATIONS IF YOUR R3 IS NOT EXACTLY AS THIS.
Despite of this warning, if you are meticulous that's all what you need.

1º After you unscrew all bottom case's screws and remove it you'll have this. You can see the right PCB (audio PCB) and the left PCB (digital PCB) covered with the aluminium paper. Underneath both is the front panel PCB.



2º Remove all the back panel's screws, the three aluminium paper's screws and the two digital PCB's screws.

3º Remove the audio PCB after removing all its connectors (in my case all the connectors are different so there's no chance to make a mistake when connect them back, but take precautions if yours is different).



4º You'll see the tempo potentiometer's pins and a seven pin connector to its left in the front panel's PCB. The tempo pot's medium pin is connected to it (most left pin of the connector). Check if this is true with your multimeter.

5º In the digital PCB there is an analog muxer/demuxer chip (LW052A). The tempo potentiometer's medium pin is connected to its pin nº1 through the seven pin connector. Check if this is true with your multimeter.



6º The tempo pot's signal comes out from the pin nº3 of this chip and it's connected to one pin of a 100 Ohm smd resistor (check this with your multimeter). The other pin is connected to the big square main chip.



7º Solder one capacitor's leg to the resistance's pin which is connected to the main chip, and the other leg must be soldered to ground. In this case there is a ground near the main chip, just scratch it with a knife and solder it to it. If your PCB is different look for a ground (often it's a thick trace, your multimeter will be helpful).

8º You're done! Surprised

Please if you do it post your results. Good Luck.

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



Joined: 30 Aug 2010
Posts: 10

PostPosted: Fri Oct 12, 2012 5:58 pm    Post subject: ? Reply with quote

Hi, just tried this fix but no luck. When I try and change the tempo under 100bpm the counter moves in 2's so 99,97,95...... and so on, making some bpm's unobtainable, the tempo does not bounce around once set.

Does the capacitor need to be of a certain type like silver mica? I just used a standard ceramic type.
Back to top
View user's profile Send private message
axxim
Platinum Member


Joined: 17 Sep 2009
Posts: 664
Location: Freiburg/Germany

PostPosted: Sat Oct 13, 2012 9:21 am    Post subject: Re: ? Reply with quote

anclibertees wrote:
Hi, just tried this fix but no luck. When I try and change the tempo under 100bpm the counter moves in 2's so 99,97,95...... and so on, making some bpm's unobtainable, the tempo does not bounce around once set.

Does the capacitor need to be of a certain type like silver mica? I just used a standard ceramic type.


This is the same on the Radias. Sometimes it helps to move the pot back and forth quickly for about a 1/4th around the desired value. With some luck then you get the stepping 100, 98, 96 instead. I always wondered why Korg never fixed this issue offering an alternative tempo input method such as selecting it thru de edit button and then setting it via the data dial or a shift key function in which the sensitivity of the tempo pot acts like a zoom (microtuning) function offering fine adjustments like +/- 10 units thru the full range of the pot once the coarse tempo is set.
_________________
_/\_><_><_|_//,_
Only a Radias, VP-770, SP-170S and iPad2
http://www.axxim.de/r3dias
Back to top
View user's profile Send private message Visit poster's website
tpantano
Platinum Member


Joined: 21 Oct 2009
Posts: 1384

PostPosted: Sun Sep 14, 2014 8:35 pm    Post subject: Reply with quote

First of all, sorry for bringing back such an old post.

Since I purchased my R3 secondhand years ago, I figured I'd give this a go myself. Unfortunately, I couldn't get it to work.

Before starting this process, I had the tempo knob issue (where it'd constantly oscillate between a few different BPM values, rendering it useless). After trying to solder in the capacitor, the tempo knob now does nothing (and yes, I am certain that I have changed the tempo mode from External to Internal, as the tempo LED starts flashing).

Any ideas as to what I did wrong? I'm presuming I either burnt out or disconnected the resistor, but giving soldering another go didn't fix it. If so, is it possible for this to be fixed by human hands– or am I out of luck?

It's not the end of the world; the rest of the keyboard still functions, I'll simply have to go back to using an external clock (as I did before). It's still a bit of a bummer, though.
_________________
Current: MS-20 Mini, Minilogue, SY77
Past: Korg R3, Volca Bass, X50, Mg Slim Phatty, Rld Gaia SH-01, Yamaha TX81Z
Have my freebie granular plug-in: https://www.muffwiggler.com/forum/viewtopic.php?t=192886
Back to top
View user's profile Send private message
Clisto1



Joined: 17 Jul 2021
Posts: 1

PostPosted: Sat Jul 17, 2021 3:02 am    Post subject: Reply with quote

Thanks for the help on this, but I see these photos have now disappeared. I do not entirely understand the last few instructions, either.

Could someone please post a photo of the finished soldering job, or describe it a little more clearly?
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 RADIAS / R3 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