Part number of Sony Trinitron wega flyback transformer model kv-bz21p40

https://www.youtube.com/watch?v=8jIe_m6CNy8

If you wish to get some details; check the site linked here. Pull up older posts. Surf the site with patience.
http://electro-medical.blogspot.com/
http://electronicshelponline.blogspot.com/
Circuit diagrams of many popular brand devices are given. Search the site by type in the "brand name" to your device, in the "Search box at the top right of the display window of the Homepage" to get gathered related posts. LOT number can be noted there.

If you wish to get some details; check the site linked here. Pull up older posts. Surf the site with patience.
http://electro-medical.blogspot.com/
http://electronicshelponline.blogspot.com/

It's the flyback transformer. Check for bad connections on the flyback and on horizontal output circuit.

Hi and welcome to the site,

Initially, the Sony KV-34HS510 uses the DA-4 Chassis. On this chassis, 7 blinks refers to the fault "Horizontal Deflection Stopped" indicating a problem with the horizontal section. Offhand, check, replace the HOut transistor and have the FBT (flyback transformer) ring tested.

Good luck and thank you for asking.

Ur high voltage transformer it dead.The big block of plastic with the red wire with a cap hook to the CRT(ur tv tube).It call the FBT,
the Flyback Transformer that thing it dead.

KV-32HS510 and KV-27HS420, seven times blink error code shows problem in Horizontal deflection circuit.

There are many possibilities like dry solder joints, weak capacitors, Horizontal transistor short or flyback transformer fried etc.

If you have little experience of TV repair and good solder skills and have necessary tools to test / check defective parts, then you can make it. you also need to have related service manual to see board location, schematics and part numbers.

+13 & -13 requires for Vertical Deflection IC and produced by Flyback Transformer, these volts will be produced IF Horizontal deflection circuit works properly. so try to check H-Out Transistor and its necessary volts / signal. Pls also mention correct Model Number to provide you more help.

It more like the tuning capacitor(s) that is connected to the HOT that is defective or a cristalized/dry solder joint nearby the flyback transformer.

Get a Qualified repairman!