Protection(When High Voltage At Protectiion Port) - JVC TH-A25 Service Manual

5.1.3 Protection(When High Voltage at Protectiion port)

5.1.3.1 In this case "LOW" for, Base port of Q12(R2003 TR) at MAIN PCB
"A"
Check DC Voltage for Speaker port
;temperature-sense S/W be operated in the Power Trans
is Turn on
Check electric potention for PBD 1, ABD1 , PD3 at DVD Power PCB
1-16 (No.MB141)
Check voltage for IC4
-12V
YES
Check Voltage
for Main AMP of Main PCB
VM, VL
YES
YES
Check the parts is normal?
;ZD6,ZD5(3.9V)
;R33,R36(27K)
R34,R37 (150 Ohm)
YES
Check normal condition for Q15(C945)
YES
NO
Check circuit for voltage(-12V)
NO
Check ABD 2,4
NO
Check circuit for DC Voltage
NO
Replace P/T, Q15
NO
Check circuit for
Diode behind position