Hi,
The sound was came from the clicking of the relay. This kind of symptoms is an indication of out-of-regulation condition on the power supply section. This is caused by faulty electrolytic capacitor. It will dropped the supply voltage and will trigger that kind of symptoms.
Faulty electrolytic capacitor mostly has a physical indication of fault like bulged/dome at the top and can be easily identified. See sample picture of faulty electrolytic capacitor below.
capacitor with bulged/dome at the top.
Check these parts on the power supply section. Once found, replaced it with same capacitance and working voltage which is printed on its body itself. Click this
LINK for more info regarding electrolytic capacitor.
If you don't have necessary tools and test instrument and can't troubleshoot the unit yourself, I would advice you to look for a qualified TV Technician to isolate the faulty parts.
Hope I helped you.
Have a nice day!
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