Hello Leonardo From this link: http://diagramas.diagramasde.com/televisores/KV-21FA210%20BA-6_Chassis.pdf download the manual. On page 7, it is indicated what symptom you have when the LED flashes four times (self-diagnosis). Luck Leonardo I already tried and the first time I was able to download the diagram, but not the next one. I'm trying to climb the manual KV-21FA210 BA-6_Chassis.pdf [8.68MB] Luck Leonardo An important thing when you are fixing not only this TV, but any device: do not change the pieces by changing them, we know that the customer is who will pay for them, but it is more important analyze and remove a piece and test it outside, and if it works well, return it to its place . It is healthier and cheaper for everyone. I would like to know if you checked the 13V indicated in the manual, the reason for the failure is a signal called I Prot. Which is derived from a problem in vertical deflection, which occurs from the One Chip (IC001, which no I am suggesting that you change), and its power and control is processed by IC545, IC565, IC561, and transistors Q521 and Q522. Nor am I suggesting that you change any of them; what is needed is that the + 13V that come from the Fly Back through the D598 diode, are present for everything to work. If there is no voltage, no vertical circuit will work, so I Prot is triggered. It measures the cathode of D598, it will give us an idea of where to go. Luck