10-6) Key Scan And Display Circuit - Samsung RS21 Service Manual

Circuit Descriptions

10-6) Key Scan and Display Circuit

1) Key Scan and display operation.
The model uses a decorder IC which 4 inputs and 9 outputs.
If the IC 9 decorder (TC4028BP) receivesd signals from
MICOM pins (3∼6), an output signal per 2 miliseconds
comes out from Q3, Q41, Q8, Q6, Q9, Q7, Q0, Q2, and Q4
pin in sequence. This signal enters to a driver IC input
terminal of the CoolSelect Zone
62783AP), then approximate 11V peaks will generate from an
output terminal as shown on the next page.
46
Power Freeze
Freezer Temp.
Ice Type
Power Cool
Fridge Temp.
Child Lock
TM PCB and IC5 (TD