Hi,
If you have a Sony KDL-E60A20 (not sure as you didn’t specify the model number) a 7 blink error code indicates an audio error and the TV will shut down.
The problem may be in the KD board or the GM board.
Here are some images taken from the [https://elektrotanya.com/sony_kdf-e55a20,kdf-e60a20_ch_la-3_sm.pdf/download.html|service manual] that shows the error codes etc.
[image|2071527]
(click on image to enlarge for better viewing)
The manual has full schematics which should help to find the problem.
Be patient when trying to download the manual. After you have clicked on the reCAPTCHA checkbox below the Document preview and then clicked on Go to Download, it takes a little while to find the file and change from ''processing'' to ''Download''. This is the link