CB Radio Galaxy Saturn Repair: Frequency Counter unstable-or no operation
The most common problem with the GALAXY SATURN frequency counter is after it is on awhile the read-out becomes unstable. Sometimes the display will quit all together. Turning the unit off and allowing it to cool for a short period of time will usually restore correct operation. This problem has been traced to a Zener Diode inside the frequency counter module. It is marked D-603. This is a 2.4 volt, 1/4 watt zener next to IC-609 (LM-7S08} regulator. This problem is also common on many other export models using the EPT210010A frequency counter board.
First be sure that the 8 volt supply is available and constant on pin 3 of IC609 ( LM7808 regulator ). Next locate D-603 in the frequency counter module. Check for 5.02 volts on the anode side of D-603. If this voltage is absent or very low replace D-603 with an NTE-5000A ( 2.4 volt, 1/2 Watt ) zener. This should restore normal operation and also prevent future problems.. We also recommend replacing C610 also. Sometimes C610 - (1OOOnf 10V electrolytic) - will develop a short, and this will cause the premature failure of D603 also.