A family member just last month had to say goodbye to one as the symptom was for BAD CAPS. As you can google BAD CAPS for symptoms, cause, repair and more I won't duplicate that here except it would be best to always supply model, year and more.
Also it needs to be shared if you are an Electronics tech or engineer as repair will involve solder irons and maybe more.
I can turn the tv on, (green light shows), but when I turn on the cable sometimes the t.v. shuts off, I get a red flashing light. I've gotten into the habit of leaving the t.v. on for awhile before I turn on the cable but I want to fix this permanently. Any suggestions?