Pump Port Test - Espresso Single (Classic)

Pump Port Test - Espresso Single (Classic)

Pump Port Test - Espresso Single (Classic)


AlertSLAYER recommends all service be performed by an experienced SLAYER Espresso trained technician. For a technician reference near you, please contact SLAYER Support at (206)-284-7171 (#1 in Directory) or email support@slayerespresso.com. 

Objective:
Troubleshoot port on circuit board responsible for sending vDC to magnetic gear pump. SLAYER Espresso Single Group;s manufactured prior to January 2020 featured magnetic gear pumps for steam tank autofill functionality and brew circuit pressure. Magnetic gear pumps rely on the circuit board to provide DC voltage proportionate to the Brew Pump Percentage setting in the Advanced Menu. Meaning, the Brew Pump Percentage is effectively the duty cycle.

Symptoms:
  1. No or low flow water through group in both brewing positions, Pre-or-Full Brew.
  2. Solenoids activate and display timers begin counting. Yet pump does not engage.
  3. Pump cuts out intermittently or under load.
  4. Low or too high pump pressure. (Adjusting Brew Pump Percentage setting has no effect.)
    1. Adjusting Magnetic Gear Pump has no effect.
    2. Values are typically between 10~30%
Parts:
  1. Espresso Single Group (Classic) Parts Diagram
    1. 30004-60100 Circuit Board, Single Group
    2. 99004-58031 Pump Assembly, Single Group 
Tools Needed:
  1. #2 Phillips Screwdriver
  2. Multimeter


Step 1: Access Circuit Board
  1. Remove rear panel to gain access to circuit board.
  2. Identify pump port:
    1. #8 in diagram below.


#1 - Main power - 24v DC from power supply
#2 - Relay
#3 - Display ribbon cable
#4 - Transducer
#5 - Level probe
#6 - Switches
#7 - RTD
#8 - Pump
#9 - Solenoids

Step 2:  Test Pump Port:
  1. Disconnect port #8.
  2. Starting on the to row, upper left corner and top to bottom, port pin orientations are as follows:
    1. 1, 2, 3, 4.
  3. Observe constant 24vDC at ports 1 + 4.
  4. Observe constant 18.5vDC at ports 1 + 2.
  5. Measuring ports 3 + 4 will provide duty cycle voltage that will increase (~1.5vDC range) as Brew Pump Percentage valve increases.
Alert
For accurate results. Test pump port with a blank portafilter engage in the group!


Questions or concerns? Please contact: support@slayerespresso.com