F) Freeze Timer (Dip Switch 9 & 10); Control Board Check Procedure; Control Board Replacement - Hoshizaki KML-351MAH Service Manual

f) Freeze Timer (dip switch 9 & 10)
Adjust to proper specification, or the unit may not operate correctly.
The freeze timer setting determines the maximum allowed freeze time to prevent
possible freeze-up issues. Upon termination of freeze timer, the control board initiates
the harvest cycle. After 2 consecutive timer terminations, the control board shuts the unit
down. In this case, see "IV.B.3. Low Ice Production" for possible solutions.
The freeze timer is factory adjusted and no adjustment is required.

4. Control Board Check Procedure

Before replacing a control board that does not show a visible defect and that you suspect
is bad, always conduct the following check procedure. This procedure will help you verify
your diagnosis.
1) Check the dip switch settings to assure that #3, 4, 7, 8, 9, & 10 are in the factory default
position. Switches 1, 2, 5, & 6 are cleaning adjustments and the settings are flexible.
2) Move the control switch to the "ICE" position. The red "POWER OK" LED should come
on. If the LED is off, check the control transformer secondary circuit. Transformer
output is 10.5V at 115V primary input. If the secondary circuit has proper voltage and
the red LED is off, the control board is bad and should be replaced.
If the secondary circuit does not have proper voltage, check the control transformer
primary circuit. Check for 115V at connector K1 terminal 10 to neutral. Always choose a
white neutral wire to establish a good neutral connection when checking voltages. For
additional checks, see "IV.B.1.[1] The icemaker will not start."
3) The "OUTPUT TEST" button provides a relay sequence test. Make sure the control
switch is in the "ICE" position, then press the "OUTPUT TEST" button. The correct
lighting sequence should be none, 2, 3, 4, 1. Some components (e.g., the compressor)
will cycle during the test. Note that the order of the relays from the outer edge of the
control board is 1, 4, 3, 2. After checking the sequence, the unit automatically starts at
the 1 minute fill cycle. If the LEDs light in a different sequence, the control board is bad
and should be replaced.

5. Control Board Replacement

The application switch located between relay X3 & X4 must be set to the "ALP" position.
The dip switches should be adjusted to the factory default settings. See "II.C.3.a) Default
Dip Switch Settings." S4 dip switch 8 must remain off.
CAUTION
Dip Switch Setting
(minutes)
No. 9 No. 10
OFF OFF
OFF ON
ON OFF
ON ON
21
Time
60
50
70
60