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Replace IC506.
Refer to Front Part
Check short
Reconnect it.
2. µ-COM Circuit
A. No Power
Does Logo appear
on the screen?
Is oscillation of
X501 normal?
Are IC503 Pins 14, 28
8
and 29 normal?
Does no DISC appear?
Does Hellow
appear at FLD?
Is P5901
connected normally?
Is P5901 Pin 23 normal?
The
waveform on A[00:21]
and D[00:15] of IC501
normal?
Are IC506 Pins 7, 8 normal?
Check the oscillation
Check short.
OK
Replace IC501
or IC503.
Check power.
(Refer to power)
If power is
normal
OK
POWER ON
1
1
YES
YES
YES
YES
YES
YES
YES
A
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
A
ELECTRICAL TROUBLESHOOTING GUIDE -2/10