I have the same issue (7 blinks, black screen) TH-42PX60U. It used to happen intermittently but start working again after being unplugged for a bit or powered from another wall outlet. Eventually, it became permanent. I have got a new TV but don't want to junk it. So, I opened the back and tried troubleshooting as indicated on several related posts on ifixit. Checking the connectors and hard reset didn't resolve the issue. Disconnecting SD and SU boards (how is this done? I alternatively disconnected the dozen wide orange ribbons on the left or the two different types of connectors each between SD/SU and the SC board. That did not resolve the 7 blink. Disconnecting the three connectors on the right of SC board (coming from SS or other boards on the right and not from SU or SD) did stop the blinking and the light becomes solid. The SS board LED light also remains solid at this point. All indications are it is the SC board (and possibly SU/SD). Disconnecting just the SC 20 connector stops the blinking (and...