Analysis and Repair: When the machine receives PAL system signals, both the black and white image and the accompanying sound are normal. Even when the color saturation is adjusted to the maximum, there is still no color. Based on the fault symptoms, the fault may be in the decoding circuit, which is inside N101 (OM8361) in this machine. Upon measuring, the chrominance subcarrier APC filter voltage at pin 33 of N101 was found to be 0V, while the voltages at other pins were normal. Checking the peripheral components of pin 33 revealed that C232 had broken down. After replacing C232, the color returned to normal.
★ When repairing issues with no color, the APC terminal of the decoding circuit is a critical point.
Fault Phenomenon: Normal black and white image, no color.
Circuit Involved: OM8361 decoding circuit.
Fault Location: Breakdown of C232 at pin 33 of OM8361, Beijing Samsung TV Repair Center.
Method, Skills, and Tips: One of the key points in repairing no-color faults.
Source of Information: Beijing Samsung TV Repair Center http://blog.tianya.cn/blogger/blog_main.asp?BlogID=3685266.
Samsung TV, normal black and white image, no color ★