Have a Magnum Opus toilet that remains open after flushing. Cycling the service switch (usually fixes most issues) didn’t work nor did removing the 12 V power to the control board. No problem, I have a spare board BUT the connectors are different and the needed ones are 700 miles away...a OH Schizer moment.
By removing the 12V power at the right moment I could get it to shut... not something the DW would be happy trying to do. Discovered led #11 would start blinking when it stayed open. Found the following Utube video that happens to have #11 blinking when a limit switch doesn’t work.
Fast forward an hour... one of the limit switches is bad and by connecting a pair of wires to its connections I can now use the toilet by shorting them together at the end of the flush cycle so the ball stays closed. This will work until I can get a replacement limit switch and a deep socket to remove the ball valve and motor.
PSC Electronics is in Columbia, MO (573-814-3131) turns out they work on a lot of different RV items including the Opus control board based on several videos I watch trying to find their location.
Naturally the hole in the side doesn’t line up with the straight slot bolt head that’s supposed to let you manually open/close the ball valve with a screw driver.