Interface Board Diagnostic Chart - Frymaster MPH14 SERIES Service Manual

1.9 Interface Board Diagnostic Chart

The following diagram and charts provide ten quick system checks that can be performed using only
a multimeter.
Diagostic LEDs
3
6
9
12
15
K1
K2
Left
Left
Latch Heat
Relay Relay
10 7 4 1
5
11 8 2
9 6 3
12
Test Points
J1 Left J2 Right
Meter Setting
12 VAC Power
24 VAC Power
*Probe Resistance (RH)
*Probe Resistance (LH)
Hi-Limit Continuity (RH)
Hi-Limit Continuity (LH)
Latch Contactor Coil (RH)
Latch Contactor Coil (LH)
Heat Contactor Coil (RH)
Heat Contactor Coil (LH)
* Disconnect 15-Pin harness from the computer/controller before testing the probe circuit.
2 1
5
4
8 7
11 10
14 13
K3 K4
Right
Right
Heat Latch
Relay Relay
4
10 7 1
8 5 2
11
12 9 6 3
Test
50 VAC Scale
50 VAC Scale
R X 1000 OHMS
R X 1000 OHMS
R X 1 OHMS
R X 1 OHMS
R X 1 OHMS
R X 1 OHMS
R X 1 OHMS
R X 1 OHMS
Diagnostic LED Legend
CMP indicates power from 12V transformer
24 indicates power from 24V transformer
HI (RH) indicates output (closed) from right latch
relay
HI (LH) indicates output (closed) from left latch
relay
HT (RH) indicates output from right heat relay
HT (LH) indicates output from left heat relay
AL (RH) indicates output (open) from right latch
relay
AL (LH) indicates output (open) from left latch
relay
Pin
1 of J2 3 of J2
2 of J2 Chassis
11 of J2 12 of J2
3 of J1 2 of J1
7 of J2 4 of J2
4 of J1 7 of J1
8 of J2 Chassis
5 of J1 Chassis
9 of J2 Chassis
6 of J1 Chassis
1-13
Pin Results
12-16 VAC
24-30 VAC
See Chart
See Chart
0 - OHMS
0 - OHMS
3-10 OHMS
3-10 OHMS
18-25 OHMS
18-25 OHMS