You'll need a TV engineer to repair it. Especially since the parts which tend to fail giving those symptoms are used in high voltage circuits and will have safety specifications. Also, an engineer may spot any underlying fault, such as arcing connections, or if there are any manufacturing circuit modifications.
First suspect would be line output transistor short circuit, putting excessive load on the power supply. Sometimes they will fail and take out a few other components with them.
They tend not to fail on their own, so the underlying cause also needs to be found, otherwise it'll likely fail again.
Often dry joints, leaky or arcing capacitors, faulty line output transformer.
There are many other faults could cause the symptoms you described but the above is one of the most common.
I'd ask for an estimate first as bills for that type of fault 'tend to fall' within a very wide range, probably £40 - £130.
Cobweb
October 2005