Μ-Com Circuit - NAD T 751 Service Manual

2. µ-COM Circuit
A. No Power
YES
Does Logo appear
on the screen?
YES
OK
1
Is oscillation of
X501 normal?
YES
Are IC501 Pins 193, 808
and 81 normal?
YES
A
POWER ON
YES
Do "Hello" appear at FLD?
NO
NO
Check the oscillation
NO
Check short.
OK
Replace IC501
or IC306.
NO
Is P3901
NO
connected normally?
Reconnect it.
Refer to Front Part
Replace IC502
3-3
YES
Check power.
(Refer to power)
If power is
normal
YES
Is P3901 Pin 8, 9, 18 normal?
NO
A
The waveform
NO NO
on 3, 5, 7 pin of IC502
normal?
YES
Replace Main B/D
1