Korg Poly800/EX800 Users

Hi,

I'm new to the forum and was hoping I could get some help. I searched for these topics

I picked up my Poly-800 used off Craigslist a few months ago and absolutely love it. It does have a few strange qualities that add to its personality though...

For one thing the entire keyboard (even when adjusting the pitch slider) is 4 semitones above the note it should be playing. For example when I play F it's actually an A. Really strange. Have any of you had this problem?

Also - within one week's time TWO of my keys have started to have loose connection when they only work when pushing down hard at the top of the key. Do any of you know a simple solution to fix this? Could it be just as simple as cleaning the contacts? I have very little technical know-how and am hesitant to crack open the Poly-800 until I have more of an idea of what needs to be done.

Any help would be greatly appreciated.

Thanks,
Dan

The tuning problem is most likely a problem with the tuning slider itself, dirty/cracked solder/lack of use for many years. Also, it could have some battery acid damage inside if any batteries were left in it.
You could try some isoproply alcohol to clean the slider. I'm not a fan of  fader lube. I think it's a poor substitute for a strip and clean, but this may be beyond your capabilities.


The rubber keyboard contacts strips need washing in a very mild detergent to get all the cack off, then you need to cotton swab the carbon contact itself with some isopropyl and then paint the contacts with Caikote 44 (follow the intructions to the letter).It's not as good as the Circuitworks Rubber Keypad Repair Kit, but will be easier to use for a beginner, and it has a longer shelf life, so you may still be able to repair some other things a couple of months down the line.


There is NO WAY to clean the contacts so they work again contrary to popular internet BS. You must replace the old carbon/conductive ink coatings on the keypad to make them work. The keypads were not designed to last this long. I have repaired many myself. Just think yourself lucky that your poly doesn't have extra contacts for velocitysensing. They are a nightmare to repair.

Take your time over it and it should be a good job.



________________________________

 From: danstetich <danstetich@...>
To: korgpolyex@yahoogroups.com 
Sent: Monday, 30 July 2012, 10:44
Subject: [korgpolyex] a few issues with my Poly-800 (Non-working keys/strangely transposed)
 

  
Hi,

I'm new to the forum and was hoping I could get some help. I searched for these topics

I picked up my Poly-800 used off Craigslist a few months ago and absolutely love it. It does have a few strange qualities that add to its personality though...

For one thing the entire keyboard (even when adjusting the pitch slider) is 4 semitones above the note it should be playing. For example when I play F it's actually an A. Really strange. Have any of you had this problem?

Also - within one week's time TWO of my keys have started to have loose connection when they only work when pushing down hard at the top of the key. Do any of you know a simple solution to fix this? Could it be just as simple as cleaning the contacts? I have very little technical know-how and am hesitant to crack open the Poly-800 until I have more of an idea of what needs to be done.

Any help would be greatly appreciated.

Thanks,
Dan

>       "There is NO WAY to clean the contacts so they work again contrary to popular internet BS. You must replace the old carbon/conductive ink coatings on the keypad to make them work. "






I've not seen the contacts for my board yet.. just what diameter, shape & size is the contacts on our boards?

I have managed to locate a supply for custom 3M Carbon Ink stickers that are approx 2.5mm diam. round (pips).  They come off a 2cm wide tape.  So there are areas around the circles to cut larger areas out if you wish.

Cost for 12 pips(2cm x 2cm) tape is about the same as the spray can carbon.  You could make 24 pips out of it if you use the spaces between pre-stamped pips.

Check out-

http://sounddoctorin.com/synthtec/parts/key.htm#polycontacts

for info and purchase.  

Bob's a really cool synth tech guy that helped me repair a coffee soaked/damaged contact board on a Roland.. not only did he have these pips, but he also had a contact board PCB to fix the carbon surface issue it had That repair couldnt use the stickers, it'd needed paint.. and he sold me a couple replacement plastic keys.

He also has a Poly 800 or two around for parts last I checked...

I have repaired contacts on an Alesis MMT-8 before now by using a paper hole puncher, to punch out circles from Aluminium/Aluminum tape used in the contruction industry. It can be bought of ebay quite cheaply or from any hardware store, but it is not as good as the keypad repair kits I mentioned. The Circuitworks repair kit I mentioned is reputedly tested for 500,000 keypresses MTBF.

I have not used the 3m dots. I have however used 3m stick on patches to repair punctures in inner tubes. Those guys know how to make a good adhesive that's for sure. This is probably the easiest way to do it.



________________________________

 From: bimmerfan222 <bperkins211@...>
To: korgpolyex@yahoogroups.com 
Sent: Monday, 30 July 2012, 12:57
Subject: [korgpolyex] Re: key contacts
 

  


>       "There is NO WAY to clean the contacts so they work again contrary to popular internet BS. You must replace the old carbon/conductive ink coatings on the keypad to make them work. "

I've not seen the contacts for my board yet.. just what diameter, shape & size is the contacts on our boards?

I have managed to locate a supply for custom 3M Carbon Ink stickers that are approx 2.5mm diam. round (pips).  They come off a 2cm wide tape.  So there are areas around the circles to cut larger areas out if you wish.

Cost for 12 pips(2cm x 2cm) tape is about the same as the spray can carbon.  You could make 24 pips out of it if you use the spaces between pre-stamped pips.

Check out-

http://sounddoctorin.com/synthtec/parts/key.htm#polycontacts

for info and purchase. 

Bob's a really cool synth tech guy that helped me repair a coffee soaked/damaged contact board on a Roland.. not only did he have these pips, but he also had a contact board PCB to fix the carbon surface issue it had That repair couldnt use the stickers, it'd needed paint.. and he sold me a couple replacement plastic keys.

He also has a Poly 800 or two around for parts last I checked...