- 3 -
3. HOLD DOWN with Horizontal Line
Open R041 and POWER ON after POWER
OFF. Check pin 30 of IC503.
Check Vcc of IC302.
Check V-out at pin 2 of
IC302.
Replace IC302.
Check pins 7 and 8 of IC501.
(SCL, SDA)
Check Vcc of IC501.
(pin 6 and 34)
Replace IC501.
Check the peripheral circuit
of U-COM.
Check R339 and D339.
Check R349 and D349.
normal
normal
normal
normal
abnormal
abnormal
Pin 1: -14V
Pin 6: +14V
abnormal
V-ramp waveform
abnormal
5. No Sound
Check L, R output of sound
PROC. Pack.
Check pins 1 and 3 of
P602A.
Check IC660 and C661.
Replace SOUND PROC.
Board.
Audio Amp
No
Check pin 8 of P601A.
Yes
No
4. Horizontal rolls
Check D408 Short/open.
Check C442.
Check Q404, Q405 and
IC301.
Replace D408.
normal
abnormal
Short or open
