Sharp VC-MH80 Service Manual page 50

FLOW CHART NO.5 TlMER (1) TROUBLESHOOTING
The fluorescent display tube fails light up.
Is the supply voltage of 5V fed to
pin (18)of IC5001?
Is the supply negative voltage of ND
Is filament voltage applied
between (l)/(2) and (53)/(54) of
the fluorescent display tube?
Also negative voltage applied
between these pins and GND.
Does the fluorescent display tube
function?
YES
Replace IC5001.
I
I
Check ATSV line.
Check negative voltage (AT-25V)
line and power circuit.
Check FL5001 and lC5001.
Check power circuit and
peripheral circuit of 09907.
Check for cracks on the fluorescent
display tube.
FLOW CHART NO.6 TIMER (2) TROUBLESHOOTTNG
Key-in input is not received.
contact?
key inputs?
YE5
Are pulses received at pins (26) ND
thru (29) of It5001 when the keys
are activated?
YE5
Check IC5001, RI701 and FIP data,
FLOW CHART NO.7 INFRARED R/C TROUBLESHOOTTNG
No operation is possible from the infrared remote control.
the receiver when the infrared
remote control is activated? '
Check between at pin (3) of
Check switch contact.
Check all the terminals of IC5001
and switches for poor soldering.
Check lines of key in and scan out.
Check ATSV and GND lines.
Replace receiver.
Replace IC701.