About 1 cm black border around the screen failure. siWservice manual download site
 siWservice manual download site
Obviously, this is high voltage stabilizing circuit malfunction caused by shrinkage of grating bulge phenomenon, the machine of high voltage stabilizing circuit as shown in figure 1. First disconnect R1501 sampling the input resistance, no the same failure phenomenon, that is, indeed, high voltage stabilizing circuit does not work. R1501 recover next, adjust the sampling resistor R155l, found that the horizontal amplitude grating indeed change cycle to service, found that in fact this is Q1503, Q1504 sent to horizontal pillow correction circuit dc level cause line deflection coil current is caused by a change). Therefore, enlarge parts of the high voltage stabilizing circuit is normal, problem could be in the output stage. As, without interrupting the magnetic saturation reactor L1514 winding phenomenon, the output tube is 01501 c (normal) should be 8.4 V, 12 V voltage obviously did not work, b has a 4.4 V voltage measurement (4.3 V) normally, but welding Q1501 check, is normal. E ready to test next extremely negative feedback resistance R1517 Ω (56), found a ring solder joint crack obviously, after repair welding of commissioning, troubleshooting.siWservice manual download site