Recently received the Chongqing TV station sent a dragon amplifier, like recording programs such as, what is certainly not low quality goods, the model is PMA-2000, has more than 10 years old, fine workmanship and styling similar to the LUXMAN Lux, material and layout is very particular, neat rules, an absolute fever machine, of sorts.DwBservice manual download site
DwBservice manual download site
Repairs to the power amplifier is not technically difficult, up better than AV amplifier, is a replacement of the control elements and parameters, make it after maintenance to keep the original sound quality.DwBservice manual download site
The TL-PMA-2000 power amplifier uses a thicker sheet metal process, so is heavy, but the design is thoughtful and base plate can be removed as a maintenance window, look down from the top, two independent transformers centered on each side is the left and right channel amplifier, the rightmost vertical with a signal interface board,DwBservice manual download site
DwBservice manual download site
According to the general law of @# of this machine, ultimately, signal processing and protection circuits, so where does the machine in this part of the circuit? Close observation, found it hidden in the CAP at the end of the following maintenance is relatively easy, it is not like our domestic manufacturers, for fear that the user removed the circuit board.DwBservice manual download site
DwBservice manual download site
This Taiwan amplifier sent to Shi of fault phenomenon is boot Hou normal work a few minutes Bell on will power protection, this paragraph machine no display, so cannot like AV amplifier as see fault, measurement the channel output points voltage normal, no protection of when output level also in zero bit, measurement protection integrated block TA7317P of 2nd feet midpoint voltage offset detection to 0.75V, description protection is due to detection to has not right of voltage caused of. After careful analysis of circuit was informed that amplifier tube output after merging four sampling diode rectifier, filter to the TA7317 the 2nd foot, filter capacitor a little bulge, replaced no DC voltage drop to 0.5 v, protection does not reappear.

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