(d) If there is no air flow, replace the restricter barb.
(e) If there is air flow, proceed to (6).
(6) Verify that the diaphragm on the control block is not defective and that
the holder is not defective. Refer to figure 5-4.
(a) Check for a defective holdback diaphragm in the control block.
(b) Replace the holdback diaphragm if necessary.
(c) If the control block holdback diaphragm is not defective, the
actuator mechanism in the handpiece holder is defective. Replace the holder.
TROUBLESHOOT A MASTER BLOCK ASSEMBLY MALFUNCTION
You may see malfunctions that originate in the master block assembly. If the unit
does not come on when the master ON-OFF valve is turned ON, use one of the
following procedures based on the ON-OFF indicator showing either ON or OFF. Refer
to figure 5-7.
a. ON-OFF Indicator Shows OFF. A possible cause is that there is no air
pressure at the inlet to the master ON-OFF valve.
(1) Verify that you have turned on the compressor and that you have fully
opened the manual shut-off valve.
(2) If so, turn the master ON-OFF valve ON and OFF while listening for a
"puff" of air from around the toggle each time you turn the valve OFF.
(3) If you can hear a "puff," the outlet is plugged, either in the cartridge valve
body or the master block.
(a) Remove the master ON-OFF valve.
(b) Clean the passages.
(4) If you cannot hear air, check for a clogged filter. If the filter is clogged,
replace it. If the filter is okay, continue with the following procedures.
(a) Check for a pinched master air tube (solid yellow) between the
filter-regulator and the master block.
(b) Check also for an obstructed barb on the master block.