Replace main encoder?

Panason · Post by **Panason** » Mon Oct 09, 2017 2:00 pm

Hi all,
The big white data encoder on my Radias is playing up. I have to turn it slowly to get values to change up/down smoothly. If i try to turn it fast to scroll through presets quickly, the values jump up/ down and i don't get anywhere.

is it time to replace the encoder and if so how feasible is it? will I need to use soldering?

Thanks in advance

LiPI · Post by **LiPI** » Tue Oct 10, 2017 6:26 am

Panason wrote:Hi all,
The big white data encoder on my Radias is playing up. I have to turn it slowly to get values to change up/down smoothly. If i try to turn it fast to scroll through presets quickly, the values jump up/ down and i don't get anywhere.

is it time to replace the encoder and if so how feasible is it? will I need to use soldering?

Thanks in advance

Hi!
Yes, you have to replace the encoder. I did it a few months ago, it was hard to solder out becouse it's soldered on both sides of the main board. If you don't have experiences about soldering ask somebody who has.
The good news, there is encoders on the market:
https://www.ebay.com/sch/i.html?_from=R ... s&_sacat=0

Best regards!

Panason · Post by **Panason** » Sat Nov 04, 2017 2:41 am

Thanks, how difficult is it to access the contact points for removing the old one and replacing it?

voip · Post by **voip** » Sat Nov 04, 2017 11:15 am

Close to a complete teardown is required to get at both sides of the printed circuit board carrying the encoder.

.

Panason · Post by **Panason** » Sat Nov 04, 2017 12:13 pm

Thanks folks. So i guess I have to pull out all the other knobs to open up the Radias ?

voip · Post by **voip** » Sat Nov 04, 2017 1:03 pm

Pulling the 39 black knobs off, plus the encoder knob, is just the start of it.

.

LiPI · Post by **LiPI** » Mon Nov 06, 2017 7:18 am

Here is a good start to disassambly the RADIAS:
http://www.korgforums.com/forum/phpBB2/ ... hp?t=43766

You have to get out the panels like this for soldering the main encoder:

https://db.tt/gYSPoMLEWE

iowagold · Post by **iowagold** » Mon Nov 06, 2017 3:37 pm

I use an iron like this one

https://www.ebay.com/itm/ELECTRIC-HEAT- ... 671166475?

it is a solder sucker iron built as one unit and is manual on the suck.

watch the heat on the board...
you can burn the board and lift the trace right off..

also there is a good product called solder wick or Chemtronics 10-25L 25' Solder Wic Wick Braid For Solder Removal from Circuits
https://www.ebay.com/itm/Chemtronics-10 ... 472100589?

I have both here in the computer repair lab.

just take your time.
re tin or reflow with fresh solder before trying the removal with 60/40 rosin core. kester brand is the best and use the super thin 30 gauge stuff
if you are good with small delicate things you will have good luck.

voip · Post by **voip** » Mon Nov 06, 2017 9:07 pm

Many thanks to LiPI for the useful info. Looking at the image in the Dropbox link, and the previous forum discussion, it would appear that the knobs don't have to come off for the teardown. The Service Manual stackup diagram has no disassembly instructions and gives the impression that the knobs have to come off in order to remove the front panel.

.

LiPI · Post by **LiPI** » Thu Nov 09, 2017 12:26 pm

Your welcome voip!

But as I mentioned above to you Panason, if you don't have enogh experience about soldering in both sided boards, you should ask some one to do it instead of you!

The replacing of the encoder is not easy like a resistor...

Get off the back of the RADIAS, then from layer to layer the panels.
It's not to complicated or hard work, but the soldering is dangerous for the printed circuits if you not enogh quick. You can burn out them very easily.

Only one knob have to remove by the front panel, the main encoder knob. Just pull. The others are as you can seen on my photo not necessary to remove.
The is more photos here: https://db.tt/9e10Q372x6

Any way I used an solderer like this: https://tomnerszerszam.hu/spd/TRP_2-73/ ... V-220V-75W since I was a child. And of course a tool; it's essential: https://tomnerszerszam.hu/spd/10212/ONSZIPPANTO

Kossi · Post by **Kossi** » Tue Dec 05, 2017 9:39 am

I was able to get the wheel fully working again on both my Radias and my microX by washing the encoders with Fader8/AID 8Clean in assembled state, knocking on wood as I had bad experiences with other contact cleaners on other synths before and replaced the encoders in the end.

No more skipping or jumping for more than a year now.

Won't fix a complete worn out encoder, but worth a try (especially taking the effort to disassemble the Radias unit into consideration).

Panason · Post by **Panason** » Wed Dec 13, 2017 8:57 pm

Thank you very much for the info, you guys are awesome. I 'll try a contact cleaner first

Panason · Post by **Panason** » Fri Dec 15, 2017 2:27 pm

Good news! I used Servisol Super 10 contact cleaner spray (available on Amazon) and it did the trick!

First I sprayed some compressed air into the encoder, turned it around for a while, then a couple of sprays of the Servisol, and more turning. Working fine now $\:D/$

EDIT: didn't fix the problem for good, see next post

Panason · Post by **Panason** » Thu Jan 04, 2018 7:29 pm

Unfortunately the fix was short-lived, and the encoder started playing up again a few days later. I just had it replaced by a qualified tech (found a replacement encoder on ebay). I'm glad I didn't attempt this on my own, it is a difficult job! I was able to watch the technician do it. There are several tiny cables and ribbons to remove so you can get to the main PCB where the encoder is, and they need the right tools to remove them. The old solder needed a lot of pumping with a desoldering iron to remove, and in the process one of the contacts on the PCB was broken and had to be fixed as well...

He emphasised that it's important to have anti-static protection when you open up electronics devices!

MMTGuy28 · Post by **MMTGuy28** » Sun Feb 17, 2019 10:40 pm

This is an old thread, but this is still good information. The problem with old rotary encoders is not always that their contacts have worn down. In fact often, in my experience, the problem is that the damping oil from the shaft has run down into the contact area and is causing trouble.

Regular contacts cleaners may help for a short time, but DeOxit G5 cleans the contacts and "conditions" them with a somewhat oily film. How this actually helps is counter-intuitive but I can tell you, as an electrical engineer, that I have yet to find a problem encoder that couldn't be fixed with several applications of G5.

Remove the knob on the encoder, drop a couple drops of G5 onto the shaft right near where the shaft disappears into the encoder. Spin the encoder in both directions about 50 revolutions. Repeat this two or three times. You may well find that you don't have to tear your favorite synth apart.

Korg Forums

Replace main encoder?

Replace main encoder?

Re: Replace main encoder?

solder sucker iron and chem wick

Try DeOxit G5 before tearing anything down.