Panasonic A-300MU type DVD machine in the process of optical disc, figure sound suddenly disappeared, all the functions of failure repair method of fault |
| Time£º2014-07-09 09:33:22 Source£ºNetwork Author£ºUnknown Clicks£º1536 |
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6nCservice manual download site
6nCservice manual download site
C1002, C1003 capacitance of the ground wire for cold bottom end (that is, the signal ground), in order to make sure the filter and signal ground in a state of high frequency zero potential. 6nCservice manual download site
6nCservice manual download site
Grid voltage polarity LC filter, despite the interference of the grid after the rectifier, filter circuit composed of VD1001, Cl011. By the circuit will be AC220V voltage rectifier, filter for about 300 v DC voltage instability, and then into three Luke to switch power supply circuit, the first path R1045, R1046 added to VD1041 tube anode; The second path switching transformer, (3) ~ (5) of Tl001 winding is added to the thick film blocks IC1011 1 foot (IC drain power field effect tube VT); After the third path starting resistance R1021, R1022 step-down to thick film IC1011 piece of 5 feet, make the feet get around 8 v voltage start, after this - a voltage to the IC circuit, and the reference circuit resistance Rl, provide oscillator with pulse width modulation and reference voltage IC in independent oscillation modulator, boot into working condition. Oscillation circuit oscillation after the pulse signal of the drive circuit of amplification and output - > R4 resistance within the IC n a power field effect tube grid, control the conduction and deadline of the tube. Tl00l (3), (5) feet of input DC voltage of the rectifier, filter after transformation of pulse voltage. When switch tube VT as Tl0111 primary side winding magnetic store energy released three times a Tl0112 Zha for winding are induced voltage is generated. Including Tl011 7) ~ winding of induction voltage VD1021 rectifier, current limiting R1023, C1021 after filtering, about 17 v (DC) voltage to IC1011 5 feet (the voltage also the R1031 resistance to the photoelectric coupler photosensitive tube collector). Because the voltage is higher than the starting voltage, the current IC1011 (5) feet at this time, mainly by the branch. 6nCservice manual download site
6nCservice manual download site
In this part of the circuit, IC1011 R2, C2 for oscillation circuit external RC network, used to determine oscillation frequency of the oscillator (the frequency set at around 200 KHZ).
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