Students in a vocational school to experiment of OCL amplifier Board, other board components installed electricity experiments were correctly, particular severe fever power power management to a Board. Other board components and the Board all transpositions still not work correctly. Board circuit diagram is shown in Figure 1.CkCservice manual download site
CkCservice manual download site
From Figure 1, we learn that this is a classic entry-level OCL circuit, there is nothing special about it. Students from the "maintenance" process component quality is no problem, according to previous maintenance experience of the power amplifier are a clear judgement, this Board had a serious "high-frequency self-excited" DC operating point is not appropriate, distributed capacitance parameter in the tipping point is a predisposing factor.CkCservice manual download site
CkCservice manual download site
TIP4C first removed 270 ω resistor voltage measurement up to 2 v, normal should be 0.5V or so. Disconnect the jumper A1015 emitter, strung in a 150 Ohm resistor, measuring 270 ω resistor voltage is 0.48V. Complex tests the installation of TIP4C, the sound clear and bright, and troubleshooting.CkCservice manual download site