2002 Ryobi (680) Ink Keys Opening Errantly

For several years now we have been experiencing what we call "the 99's" when an ink key opens itself to wide-open (99) and does it on its own during a press run (regardless of if the "lock" button is on on the console). Has anyone else experienced this and was there a remedy?

We have been advised by our service tech it's caused by too much oil/solvent getting into the connections to the ink key motors causing the errant behavior. We just got our butt kicked on it happening on magenta where two side-by-side keys did it and ruined about 500 sheets before it was noticed. We had to washup the unit and start over and zero all the keys.

We are going to attempt to take all our motors out (one unit at a time) and use some electronic contact cleaner on the ribbon cable and motor connections to clean the up and see if that helps. We also plan to exercise the keys by hand and lube as needed to free up any that are stuck.

For years, we've always thought a key was dead when it stopped operating, but I think we've come to the conclusion that it's more to do with if the key is able to move freely or not (by turning the large gear that the ink key motor drives with our thumb when the motor is out of the way). If there is heavy resistance, there's no way a small motor has the torque to turn the gear. I recently purchased a small 12 volt power supply to bench test our motors, and came to find most still operate fine (usually in both directions; you can change direction by changing the polarity of the power being supplied).

Anyway, if anyone has had experience with this, any tips or solutions would be appreciated.

 

Have come across this issue a few times you're plan sounds good, pressman should always make it a part of his routine to inspect the the ink fountains during the press run .if you're keys jump open you will see right away

 

if some number blink because potensio and mechanical of ink key not synchronize, you must zero adjusment

 

Can you share the process on how you zero the key(s)?

 

Take out the ink key motor block and turn the ink key gear clockwise (if im not forget) until stop and turn back 5 degree
After that u make poyensio zero, turn vlockwise or counter clockwise, u see ink zone display at pcsg, if already 0, stop and i stall the motor ink key block

 

After already mechanical 0 and potensio 0 install ink key block to machine