TROUBLESHOOTING
Nature of Trouble No power Faulty Block Power IC (LA5668N) Power jack No sound at all Power IC (LA5668N) Power amp (LA4127) Main clock generator CPU (CDT109-005) Checkpoint Pin 2 should have +9 V. Jack contact. Pin 6 should have +5 V. Check output signals of pins 1 and 20. Check oscillation at pin 105 of CPU. Pin 6 should receive a trigger pulse when turning on the power switch. Check signals DATA, BCLK, WCK1 and LRCK of pins 107, 109, 111, and 112. ROM (HN62414PD25) Reset IC (S8053ALR) Certain keys or switches do not function A certain key or switch does not function Distorted sound Key and switch matrix Key and switch matrix Power IC (LA5668N) ROM (HN62414PD25) CPU (CDT109-005) Check address/data bus. Pin 1 should provide a low level pulse when the AC adapter is connected. Open circuit on KO or KI line. Dust on the con tact. Check voltages of pins 2 (+9 V) and 6 (+ 5 V). Check address/data bus.
