Samsung MAX-557 - Troubleshooting

4. Troubleshooting
4-1. The Amplifier section
4-1-1. Power malfunction
i Check the power
FRONT
PCB
X
Main
PCB
ee
u-com VDD(5V) normal? >———————» <_ RIC 1(BA3950)#6:20V circuit; RD2, RD3(IN5392)
pin
no.18,47,90
Input
voltage
AND,
At
the
base
of
FRONT
of
VICI
normal?
PCB,
RF3,4(T2A
250V)
Replace RIC1
Check; FRONT PCB
x
XR3,4
FRONT PCB
Does UX1(12MHz)
it oscillate?
FRONT PCB
>< POSNS voltage normal?
pin no.29 ; 4.5V.
POSNS circuit
Check ; MAIN PCB
RD5,RR3,RC4,RR4,RR2
RQ4 POSNS circuit
FRONT PCB
When the power is
ON, 'H' displays
at no.91?(5V)
Replace MICOM
At the base of
MAIN PCB,RIC1 BA3950
pin no.10 High
display?
Connect FRONT PCB and MAIN PCB.
Check the connector Main PCB
Wafer CCW1, CCW2.
Replace RIC1
-9- MAX-550