The upper circuit board is a component which the lower, main circuit utilizes to carry out some of the functions to operate the marker. Smart Parts prefers to keep their electronics as integrated as possible (meaning everything possible is attached to a circuit board, instead of being connected using wires and such), so that's the reason the upper board is used in the Shocker design.
Solenoid Connection to Upper Board: 
The relation of the solenoids with the upper board is simple in this regard. The upper board is NOT removable with the Parker solenoids. The two coil terminals stick up out of the coil housing, and are soldered directly to the board. The board therefore cannot be removed unless it is desoldered from the board. I personally do not recommend doing this for any reason, unless you are absolutely forced to do so. I recommend this soldering task only for advanced technicians, since desoldering the solenoid is a very delicate operation and the coil terminals are extremely fragile.
Functions of the Upper Board: 
The upper board doesn't contain any programming of its own, nor does it direct any operations of the marker. It rather houses a collection of various circuit components which are used to perform those actions, when directed to do so by the lower board. Here's a list of parts:
· Energize the solenoid (uses a FET transistor, clamping diode, and two resistors to stabalize for the FET signal)
· Operate the powerswitch (uses the powerswitch all by itself)
· Operate the Vision system (uses a 1-mm FPC connector and two resistors)
· Activate the board indicator LED (uses a resistor, FET transistor, LED diode, and resistor for the FET signal).
Here are some technical specifications on the upper board itself:
· Wire harness connector is a 10-point, shrouded, side-entry type JST eSH series header, JST part number BM10B-SRSS-TB. Wire harness is 32 AWG wire connected between two protrusion-less housings, JST part number SHR-10V-S-B.
· The powerswitch functions off 9v from the lower board. It doesn't interact with any other part of the board; it's self-contained on the upper board. Powerswitch is a subminiature side-actuated tactile switches, ITT CANNON part number KSS321G (7mmx3.5mmx1.6mm).
· The solenoid functions off regulated 7v from the lower board. A rectifier diode is used to preserve the FET responsible for switching on the solenoid current.
· The LED functions off the same 7v supply as the solenoid, dropped down by a resistor. no rectifier is used.
· Vision system functions off regulated 5v from the lower board. A resistor drops the emitter eye current. Another resistor is provided for a pull-down effect on the detector's signal.
A reverse-engineered circuit schematic of the upper board can be found below, which includes a schematic for the stock lower board as well. Specifications for the lower board can be found on its page (see the Related Links section).
Vision System Hardware:
The Vision anti-chop eye system used on the Shocker NXT uses very self-contained parts and is easy to maintain. The Vision eyes themselves are attached to an FPC (flexible printed circuit, or simply eye ribbon for short), which is Y-shaped to split the two sides of the body. The eyes are held in place by the detent/eye covers, which use a 4-48 x 5/32" integrated screw, that uses a 1/16" allen wrench for removal.
Do not overtighten the eye cover screw. It is easy to strip out and this will cause a lot of problems in the future. No screw on the marker needs to be tightened as far down as possible.
The Shocker body is internally milled in such a way that the eye ribbon can be directed to the upper board through the inside of the marker, instead of being wrapped around the side like on some other markers. When installing the eyes into the Shocker body, the clear-tinted eye (emitter) goes on the left side whereas the opaque/dark-tinted eye (detector) goes on the left. Install the eyes one at a time, since they both won't fit down through the eye ribbon canal at once
It's true that the eye system will function with the eyes on either side of the chamber, however you will find it more difficult to install them backwards.
The eye used on the Shocker/Impulse will only function if plugged into the connector the correct way. The silver contacts must face away from the board/body.
Vision Eye & Cover Reassembly:
This involves inserting the eyes into position and carefully installing the covers back on top of them. The first step is to take one of the eyes (emitter or detector) and insert it through the ribbon canal on the underside of the body. The clear-tinted eye goes in the left of the body whereas the opaque/dark eye goes in the right. It doesn't matter which you choose first, but in these pictures I start with the clear emitter and do the detector second.
The first step is to insert the eye up through the common canal in the bottom of the body, then guide it through to the correct side of the body. This can take a few seconds/minutes to accomplish; feel free to use a small tool to help guide the eye around the corner.
Align the eye onto the its base under the eye cover. Push it down into position and it should stay relatively in place.
Insert a 1/16" allen wrench into the screw head in the corresponding eye cover eye screw (installed in the eye cover, as shown below). Align the eye cover onto its base in the body and make sure it's straight.
Screw the eye screw down and lightly tighten it in place. Do not overtighten the eye screw.
Insert the opposite eye down into the ribbon canal and slide it around to the eye cover base like the first eye. Push it into position like the first eye.
Install the corresponding eye cover in place, again without overtightening the eye screw.
Flip the body upside-down and plug the eye ribbon into the brown connector on the upper board. The silver contacts face away from the board/solenoid. If the eyes are installed backwards then you'll have to twist the ribbon around to connect it corectly.
Vision Eye Cover:
This is described on the Breech section page (refer to the related links at the bottom of this page).
Grip Screw Damage:
If you purchase aftermarket grips for your marker, you must be sure they will not damage the circuit board by screwing the grip screws in too far. Please refer to the Grip Screw Damage Information link in the Related Links section.
Overview:
· The upper board controls several functions necessary to operate the marker.
· Vision eye ribbon is isntalled through the middle of the Shocker body; the eyes are held in position by the installed eye covers.
· Aftermarket grips that are more thin than the stock ones can cause damage to the upper board.
Related Links:
· General electroincs troubleshooting
· NXT Vision system troubleshooting
· NXT lower circuit board
· Powerswitch actuator
· Grip screw damage information
· Powerswitch repair
Navigation:
Tech index -> Shocker NXT -> Parts of a Shocker -> Upper circuit board & Vision system