Вставка
- Опубліковано 7 вер 2024
- CHINA TV 21"NORMAL PCB
MAIN IC 8895CSNG 7DN5
EHT BSC25-T1010A
VERTICAL IC LA78040
SOUND IC TDA2003
TRANSISTOR POWER SUPPLY
NO EHT PROBLEM
1.Power on/Check video output supply voltage---low.No genarate eht.
2.Check power on voltage pin No.64------ok.
3.Check 8V pin No.17------ok.
4.Check 5V pin No.36------ok.
5.Check driver transistor collector voltage----ok.
6.Check driver transistor base voltage----missing.
7.Check RGB supply voltage-----ok.
8.Supply resistor R209(270 ohms) input voltage ok. But resistor output voltage missing. That means main ic RGB supply pin No.49 voltage missing.
9.Power off/Measure supply resistor R209(270 ohms)----ok.
10.Open three lid from pcb
a) Main ic pin 49.
b)condenser.
c) Capacitor.
11.Check ohms pin 49------high.
12.Check ohms condenser lid----high.
13.Check ohms capacitor C211(103) lid---low.
14.Open the capacitor.
15.Then-----
