Taken from
www.zdspb.com
Solenoid:
The solenoid is a "latching" type valve which uses magnetic fields of the surrounding material to reset it while idle. As a result, the solenoid's internal armature can get lodged in the incorrect position and prevent it from sealing up. If this happens you may have to disassemble the valve.
Alternately, the manual doesn't make mention of solenoid maintenance (not that I can recall anyway) but you may wish to clean it out after a while, once it gets filled with grease. Greasy air pressure will be shunted through the solenoid for each pressurized firing, so you may wish to clean it out after a while. This would likely be an infrequent cleaning.
Anyways, the solenoid is held together by three small phillips-head screws, accessed through the top. I've found that you need a perfectly-shaped screwdriver to remove these, or you may strip them out.
When the endcap comes off, there will be one metric o-ring between it and the solenoid housing. It may stick to the endcap or stick to the housing; keep track of it either way (in the below picture, it stuck to the endcap).
The armature sticks out the top of the solenoid housing; it can be removed by pulling it straight out.
The armature is a two-piece component with a seat-seal at each end. Both ends should be reasonably clean as well as the main shaft too. The opposing seat surfaces down inside the solenoid housing and up inside the endcap can be cleaned.
During reassembly, reinsert the solenoid armature down into the housing with the thin, brass (yellow) end facing up/out. You need to be able to view the top port in the armature before reinstalling the endcap. If you can't see the port, pull the solenoid up slightly and it will "suspend" itself in position. Gently reinstall the endcap once it's set.
If the marker is pressurized with the armature in the wrong position, it'll leak and won't seal up. The solenoid is designed to reset itself after being energized, but you never know if it'll go wrong once and foul everything up. The trick that's been circulating for resetting the armature is to crank the dwell setting all the way up (or to an abnormally high setting with an aftermarket board) which should smack the solenoid into the correct position. However if that doesn't work you'll have to take the solenoid apart and reset it yourself, manually.
