Μ-Com Circuit - NAD T531B 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 IC503 Pins 14, 288
and 29 normal?
YES
A
Does no DISC appear?
NO
NO
NO
Check the oscillation
NO
Check short.
OK
Replace IC501
or IC503.
POWER ON
NO
Does Hello
appear at FLD?
Is P5901
NO
connected normally?
Reconnect it.
Refer to Front Part
Check short
Replace IC506.
3-3
YES
Check power.
(Refer to power)
If power is
normal
NO
Is P5901 Pin 23 normal?
YES
A
The
NO NO
waveform on A[00:21]
and D[00:15] of IC501
normal?
YES
NO
Are IC506 Pins 7, 8 normal?
YES
Replace Main B/D.
1