Sharp TU-X1U Service Manual page 50

TU-X1U
Dose the signal come to 1 pin of LAN-jack J9501? (see fig-1, fig-2)
Dose the signal come to 1pin of IC9501? (see fig-2)
(IC9501:RTL8100C)
Dose the 3.3Vdc come to VDD33/AVDD33 of IC9501?
Dose the 2.5Vdc come to VDD25/AVDD25 of IC9501?
Dose the clock signal come to 121pin of IC9501? (25MHz, 3.3V)
Dose the 200kHz clock signal come to 2pin of IC9502?
(IC9502:BR93L4RW)
Check IC9501 and its peripheral circuits.
fig-1. LAN-jack J9501
When IC9502 is defective, it becomes a MAIN unit exchange.
No connect network
NO
NO
YES
YES
YES
1pin
YES Check the interface device and peripheral circuits. (power-
LED of hub, LINK-LED of hub)
YES Check the line between J9501 and IC9501.
Check the LAN-jack J9501.
NO Check the power-circuits of 3.3V.
Check Q9501. (2.5V reg-Tr)
NO Check the line between X9501 and IC9501.
Check the crystal X9501. (SCA176WJ)
NO Check the line between IC9502 and IC9501.
Check the LAN-jack J9501.
fig-2
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