Troy PL757A-digital tuning radios using variable capacitance diodes instead of conventional combined mechanical variable capacitor tuning circuit, by TA7358AP (tuner high level) and TA8132AN (FM, AM and detection), and AM FM high level, drop in, stereo decoding (including Mw, SW), high-level, and detection in back, driven by dual mono power amplifier cxA1622 speakers or headphones. Operation controls and displays by Toshiba's single-chip PLL (phase locked loop) digital tuning cPu (microprocessor) Tc9316F, operating matrix components, such as buttons and the LcD liquid crystal display,Buyservice manual download site
Buyservice manual download site
Tc9316F contains 130MHz LCD and FM preset crossover drive, a CPu can constitute a complete digital tuner control system. Adopt international standard bands, have a very high sensitivity and s/n ratio, sounding, used electronic clock can be made at leisure time, forgot to turn off the machine has automatic timed shutdown function for as long as 90 minutes to save energy. Is a handful of exquisite homemade radios, quite popular with consumers.Buyservice manual download site
Buyservice manual download site
The radio shows, and show two pieces of circuit boards, connected by a 12-core plugins, schematic circuit as shown in Figure 1, Figure 2, respectively. Through service examples, on the causes of common trouble and overhaul method for detailed analysis and discussion, for your reference.Buyservice manual download site
Buyservice manual download site
Example 1: whether you use internal battery or an external rectifier, simply press power switch, will appear on the LCD screen are weak "battery replacement" character and flashing, machine does not work.Buyservice manual download site
Analysis of repair: the organic battery 4. 5V power supply, external rectifier power supply 4. Two options of 5V power supply, with an external rectifier power supply is 220V AC after buck, Rectifier, filter, is composed of three stable fixed voltage regulator 5V output by tandem rectifier diodes,Buyservice manual download site
Buyservice manual download site
Due to the diode forward voltage drop is 0.7V, so the power jack into the radio DcJACK voltage about 4. About 3V.

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