Hello I repair community, I do not usually mess with tube TVs so that is why I turn to their experience to see if they can give me a hand. Today, I picked up a 21-inch Sony Wega Trinitron TV model KV-21FS140. When turned on it turns on and the screen looks sharp, but dyed red. In AV mode it looks black with thin blue lines that cross the screen horizontally (lag lines?). The power LED after a little while turns from green to red and starts to flash 5 times, which according to the service manual, is a subject with the IK "CRT Cathode current detection reference pulse output is small" (the pulse detection of current reference of the output CRT cathode is small). I opened the TV and reviewed the welds of the insert connected to the canyon without any change. Finally take some voltages to have some reference. Pin 6 (VDD) of the TDA6108 delivers 196.7 V The cathodes deliver the following voltages KB = 59.2 V KG = 62.6V The KR = fluctuates constantly between 142/145 V The last thing I tried was the old trick of touching each of the cathodes with a cable connected at one end to the RF tuner and at the other a 15 K resistor and what caught my attention is that instead of seeing a red screen another green and one blue, the three cathodes gave red patalla. Well, in my inexperience that is all I can think of at the moment, thank you very much for having bothered to read all this paragraph until here :) and if anyone comes up with something and can give me some advice, much More than grateful. Regards. PD: I have no more instruments than a multimeter, the oscilloscope I owe them: P