After the boot image has no color, but sometimes there is no change color after. But the small picture is normal. V4Kservice manual download site
Color aberration. The fault should be in the chroma decoding circuit. This machine is EUR07 movement. YC processing circuit process such as graphic: by the figure above. The analysis of the main picture chroma decoding is mainly composed of DG box IC1301 to complete, should pay attention to its normal working conditions, such as the IIC bus, line, synchronous pulse. VCC power supply and the oscillation work is normal or not. V4Kservice manual download site
 V4Kservice manual download site
 V4Kservice manual download site
(1) trial observation. Large images of the AV/TV disorder and with no color. About image jitter, but little picture, AV output is normal, normal Y/PB/PR is not normal. (2) is introspected all the data are OK. That is not caused as a result of the IIC bus. V4Kservice manual download site
(3) after teardown measurement DG IC1301 working conditions inside the box, confirm that the bus voltage, power VCC, H, V synchronous pulse are normal. Input IC1301 84 feet, 62 feet of C Y signal waveforms are normal, to rule out the possibility of the circuit before IC1301 bad. IC1301 measuring 94 feet in the presence of fault vibration crystal oscillation waveform instability. Vibration analysis is likely to be empty welding, IC1301 and peripheral components failure after repair welding. (4) change the crystals X1301 after troubleshooting. V4Kservice manual download site
Product's replacement crystals X1301 (parts: TSSA171) began with a small image processing circuit first crystal vibration and its displacement results in the big picture OK. Small picture disorders, again after the comparative analysis showed that the crystals with TC - 29 p48g DG container of crystal vibration model, the same normal after replacement. V4Kservice manual download site
For DG box maintenance now, because of its internal various IC pin function is difficult to fully understand in detail, combined with the maintenance experience, lack of the data, so the advice before the maintenance will be based on careful observation and analysis of failure judging from the circuit functions. First troubleshoot circuit involved respectively, find out the fault point, then start from the details. To measure the key, don't blindly to DG box of repair welding. Pay attention to the main working conditions, the IC will get twice the result with half the effect. Such as in this case the fault from picture this phenomenon is easy to conclude that in the normal point of failure in the IC1301 circuits.

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