Sharp VC-A422U, Service Manual

Page: 48 / 77

48
VC-A422U
VC-H822U
YES YES YES YES
NO NO NO
NO NO
NO
FLOW CHART NO.22
Is there a signal inputed at each terminal of IC651 as shown in table?
Front input terminal Rear input terminal Tuner audio terminal
L-ch R-ch pin(15) pin(10) pin(14) pin(9)
Check the peripheral circuit of front input terminal. Check the peripheral circuit of rear input terminal. Is there a SIF signal from pin(24) of Tuner?
Line output terminal :
Check the line ranging from pins(53) and (57) of IC651 to the audio output terminal.
RF output terminal : Check the line ranging from pin(59) of IC651 to pin(2) of tuner
(TU101).
Is the Sub carrier signal (3.58MHz, about 900mVp-p) input into(45) of IC651?
Is "H" level applied at pin(45) of IC651?
NO
Check the line between pin(36) of IC651 and pin(22) of IC701.
Is "L" level applied at pin(36) of IC651?
NO
Check the regulator circuit of Hi-Fi 5V and PC 9V.
Is 5V applied to pin(40) of IC651, 9V applied to pin(58).
YES YES
NO
Check the line between pins(43), (42) of IC651 and pins(17), (18) of IC701.
Is there a serial data and clock signal at pins(43), (42) of IC651 respectively?
Check the line between X501 and pin(45) of IC651.
Line output terminal : Is there an audio signal output at pins(53) and (57) of IC651? RF output terminal : Is there an audio signal output at pin(59) of IC651?
Replace IC651.
No Hi-Fi E-E sound heard.
pin(48)
Hi-Fi sound cannot be recorded
(E-E mode is normal).
YES
NO YES
YES
NO
NO
NO
Is the record FM signal output to the pins(21) to (24) (ch-1)/pins(21) and (22) (ch-2) of
Check the AH-MZ connector.
Is the voltage of pin(29) of IC651 about 3.7V?
Check line of Hi-Fi 5V.
Check Hi-Fi REC CTL line.
Replace IC651.
Is 5V applied to pin(25) of IC651.
FLOW CHART NO.23
Is the terminal voltage (REC AGC. ADJ.) at pin(37) of IC651 normal?
Hi-Fi sound cannot be played back
(E-E mode is normal).
Is the playback envelope signal output to pins(29) and (30) of IC651? (300 mVp-p)
YES
YES
NO
NO
Replace IC651.
Replace IC651.
Is A-H.SW.P input into pin(27) of IC651?
Check the A-H.SW.P. line from pin(27) of IC651 to pin(28) of IC701.
FLOW CHART NO.24
Recording in linear audio is impossible
(Hi-Fi E-E mode is normal).
YES YES YES YES
NO NO NO
Is the audio signal input into pin(8) of IC201?
Is pin(99) of IC201 in "L" level?
Does the bias oscillation circuit operate normally?
Is the audio signal on which bias signal is superposed output to pin(4) of IC201?
Check the AA-MH harness and A/C head.
Check the bias oscillation circuit (T601, Q602, Q603). Check the line between pin(61) of IC651 and pin(8) of IC201. Check the periphery of pin(99) of IC201. (R617)
FLOW CHART NO.25