CB Tune-Up Manual Master Edition/Volume 2/CB Repair Tips

President Lincoln

Unit lights up, has sound from speaker, but no channel display. Loss of normal operation.

Locate the M7805 regulator on the main PLL board. Check for 5 Volts on the #3 leg of this component. If you find this voltage is absent - you will need to replace the M7805 regulator. A direct replacement part number for the M7805 regulator is NTE 960. Next replace the sub-miniature 1000 μF 6.3 Volt electrolytic directly behind the 64 pin chip with a sub-miniature 1000 μF 10 Volt capacitor. This capacitor normally becomes shorted in most all the units, thus causing the 7805 regulator to fail in most cases... Changing this electrolytic from a 1000 μF 6.3 Volt to a 1000 μF 10 V will help to eliminate-any future problems.