Analysis shows that the oscillation circuit does not work. Check if K1 is bad, the battery has no power, R3, L1, L2 is open, VT3, Cl is open circuit or short circuit, LED3 circuit. VT3 available beta = 80~120 2SC2500, 2SD651, 2SDl162 or 3DKIOB substitution. T1 can rewind the original core (L1 φ 0.33mm enameled wire winding 18 turns, L2 φ 0.21mm enameled wire winding 15 turns, L3 φ 0.08mm enameled wire winding 1200 turgwPservice manual download site