Television safety (help)

I have a TV that decides to turn off after about 5 to 20 minutes. I found several components with the soldier lifted from the track. After soldiering them it stayed on for longer, I then found to of the rectifier diodes were blown and another that I cannot identify to replace, it has the numbers (30 40 and three dots). it is a 51 cm sharp television about eight years old. I know about releasing the charge from the capacitor that is the one that will throw you across the room. I would like to be able to look for problems with the television powered up. I will only proceed (only) if I am confident I can do so (safely) so could someone please help me with the (do and don'ts), safety procedures.

Thanks in advance.

My advise: Please don't do it again. Wind it up and go for a service technician or buy a new LED TV.

It sounds as though you have little experience of working with high voltages, so in the interests of safety I would urge you to follow the advice above.

lol,but i wanna give it a shot.anyway,thank you very much