Main Board Section - Panasonic UF-5500 Service Manual

MAC through the MII. TXD[3..0] has no effect when TXEN is de-asserted.
• RMII Tx Mode: The TXD[1:0] bits are synchronous with REF_CLK. For each clock period in which TX_EN is asserted, two bits of
data are received by the PHY from the MAC.

11.2.20. Main Board Section

3.3V / 1.2V Troubleshooting Guide (1)
3.3 V / 1.2 V Troubleshooting(1)
Is the input voltage
24V pin8 of CN504 on the
MAIN Board correct?
OK
Is the 3.3V output
voltage correct?
OK
(1.2V NG)
Replace IC800 on
the MAIN Board.
OK
Is the problem
still occurred?
OK
END
Are the resistance
NG
value of 24V more
than50 ?
OK
Check PSU and Harness between
CN504 and PSU and replace the
parts having the problem.
Is the problem
still occurred?
OK
END
NG Is the 1.2V output
voltage correct?
OK
(3.3V NG)
NG
NG
Check C807, C808, C501, C503,
C505, C524, C525, IC502, IC700,
Q509, Q523 on the main board and
replace the parts having the problem.
Is the problem
still occurred?
OK
END
Replace the
NG
MAIN Board.
NG
(1.2V & 3.3V NG)
3.3V / 1.2V Troubleshooting(2)
195
UF-5500 / 4500
Replace the
NG
MAIN Board.