SHARP VC-H725X
Manual de Servicio

NO.22 Hi-Fi TROUBLESHOOTING(2) (Hi-Fi Models) FLOW CHART NO.24 LINEAR SOUND MODE TROUBLESHOOTING (1)

VC-A310X/NZ VC-H725X VC-H730X/NZ

No linear sound recording (E-E mode is possible) No Hi-Fi sound recording(E-E mode is possible)
NO Check the AUDIO MUTE (H) line between pin

Is there "L" level at pin (99) of IC201? (99) IC201 and pin (81) of IC701.
NO Replace IC651. YES

Check peripheral circuit of IC651 as YES shown in table. Is there a signal at pin(4) of IC201? Replace IC201.

L-ch pins(16),(17),(18),(19)

R-ch pins(35),(34),(33),(32) NO

Is the supply voltage 12V fed to pin(2) of Check PC 12V line.
YES YES

YES T601? Check Hi-Fi 5V line.

NO

Is there signal (Bias) at pin (5) of T601? Q603) and FE BIAS CTL line.
of IC651?
NO Is there signal (Bias + Audio sig.) at pin (6)
YES of T601? NO Is the supply voltage of 5V fed to pin(25)

Check the Bias oscillation circuit(T601,Q602,
Is there REC FM signal outputted to the pins(21) (24)(ch-1)/pins(21) to (22)(ch-2)

of IC651 ? YES

YES Check peripheral circuits of T601.

Is there H level at pin(29) of IC651? Check AH-MZ harness.
YES
NO YES

Check the MH-AM harness and A/C head.

Check or replace the cylinder. Check the Hi-Fi CTL (H) line between pin (29) IC651and pin(22) of IC701.

FLOW CHART NO.25 LINEAR SOUND MODE TROUBLESHOOTING (2) YES No linear sound playback (E-E mode is possible) Check the record AGC setting resistor
R678 at pin(37) of IC651.

46
Is there a signal at pin(100) of IC201?
YES YES

Are MH-AA harness and the PB AMP. Replace IC651. NO peripheral parts normal?

FLOW CHART NO.23 Hi-Fi SOUND MODE TROUBLESHOOTING(3) (Hi-Fi Models) Clean A/C Head.
YES

No Hi-Fi sound playback(E-E mode is possible) NO Is the azimuth height of A/C head properly
adjusted?

Replace IC651. YES
YES Replace A/C head.

Readjust azimuth height. Is there playback envelope signal(about NO Is the supply voltage of 5V fed to pin(25) 300mVp-p) outputted to the pins(29),(30) of IC651? NO

of IC651? A-H.SW.P. signal pin(27) Is there "L" level at pin (99) of IC201? YES (99) IC201 and pin (81) of IC701. IC651?
NO

Check the AUDIO MUTE (H) line between pin

YES Check peripheral circuit of IC651 as shown in table. NO

L-ch pins(16),(17),(18),(19) Check the A-H.SW.P. line between pin

Is there a signal at pin(11) of IC201? Replace IC201.
NO

R-ch pins(35),(34),(33),(32) YES (27) IC651 and pin(28) of IC701.

YES Is there audio signal inputted at pin(62) Check line between pin (11) of IC201 and

Replace IC651. IC651? pin (62) of IC651.