Practical guide to chassis repair - Free

Practical guide to chassis repair
VGA/SVGA (32 – 38 kHz)
Horizontal Deflexion (Fig.17)
Defect:
• No high tension, check:
1. Transistor Q23 = BU2520A.
2. Transformer T2 = EHT.
3. Integrated Circuit U5 = MC14046B.
4. Transistor MOSFET Q4 = IRF510.
5. Electrolytic Capacitor C12 = 10µF 160 V.
6. Diode D41 = BYV26E.
Synchronism – horizontal oscillator
Defect:
• Synchronism does not work, check:
1. Integrated Circuit U2 = 74LS86 (Fig.18).
2. Integrated Circuit U5 = MC14046B (Fig.17).
3. Transistors Q16 – Q18 = BC547 (Fig.18).
4. Transistor Q26 = BC557 (Fig.18).
5. Trimmer VR2 = 22 kΩ (Free Freq.) (adjust frequency) (Fig.17).
Via Nuova Poggioreale 163 A/B 36 Tel: 0039 / 081281582
80143 Napoli (Italy) www.gevin.com Fax: 0039 / 0815546641