Check 3 — Solenoid CO₂_In
Test each solenoid for stuck-open and stuck-closed failures with CO2 on the CO2_In port — Health Check Idents D through J.
Check 3 — Solenoid function on CO₂_In
Verify each solenoid opens and closes correctly by observing gas flow at the Stone, Arm, and Vent ports when buttons are pressed in Test Mode. This check proves two things: no solenoid leaks at rest, and each button operates the correct solenoid.
Preconditions
Each button operates one internal solenoid.
Button-to-solenoid mapping
| Button | Solenoid operated | Port |
|---|---|---|
| Up | Head_Transfer | ARM |
| Down | CO₂_in | STONE |
| Enter | Vent | Vent valve |
At rest — nothing should flow
With CO₂ connected and no buttons pressed, confirm there is no gas flowing from any port. Any flow at rest means a solenoid is stuck open.
| Ident | Confirm no flow from | Pass |
|---|---|---|
| D | Stone connection | No flow |
| E | Arm connection | No flow |
| F | Vent valve | No flow |
| G | Flow meter ball | Ball down, no flow |
Button tests — each button pulses the right port
Press and hold each button in turn and observe the result.
| Ident | Press and hold | Expected result |
|---|---|---|
| H | Up | Gas pulses out of the Arm connection |
| I | Down | Gas pulses out of the Stone connection, and the flow meter ball bounces |
| J | Enter | No gas flows from anywhere — you should hear a quiet click |
Ident J is a listening test
Check J is a listening test, not a flow test. With CO₂ on the CO₂_In port, operating the vent solenoid should not release gas. The click confirms the solenoid is actuating.
If a check fails
| Ident | Symptom | Likely cause / actions |
|---|---|---|
| D | Gas continuously flowing through stone connection | CO₂_in solenoid stuck OPEN — change the CO₂_in solenoid. |
| E | Gas continuously flowing through arm connection | Head_Transfer solenoid stuck OPEN — change the Head_Transfer solenoid. |
| F | Gas flowing through both arm and vent | Change the Head_Transfer and Vent solenoids — both stuck OPEN. |
| G | Flow meter ball is up | Same cause as D — change the CO₂_in solenoid, stuck OPEN. |
| H | Up pressed, gas does not pulse through arm | Head_Transfer solenoid stuck CLOSED — change the Head_Transfer solenoid. |
| I | Down pressed, gas does not pulse through stone | 1. Confirm the flow meter is not turned all the way off — rotate the knob counterclockwise and retest. 2. If it still does not pulse, change the CO₂_in solenoid, stuck CLOSED. |
| J | Enter pressed, no clicking sound | 1. Confirm the vent valve is not physically open. 2. Change the Vent solenoid, stuck CLOSED. |
Next step
Check 4 — Solenoid ARM
Move CO₂ to the ARM port and repeat the solenoid tests.