IndiaReFix - Laptop & TV Repair Forum

hello, pressing power on / off turns on both led power and power-on, turns the fan for two seconds, turns hd, but the screen remains black, after 5 sec everything turns off, then after another 5 sec it turns on again, everything as before with black screen, I tried to replace the ram but nothing changes, removed the battery but nothing changes, I checked the main voltages and they are all present, I also tried other CPUs but no results,I reprogrammed the bios, but without results, some advice?
thanks