TV SHARP 51GT-25S

[caso]

Good day

I have a problem whith the horizontal output on this TV set.

Because I haven´t the transístor BU508DFI, I used a copy (S2055N) but after 30 minutes, it fail down.

A friend tould me that in this model it is necessary to use the original taransístor BU508DFI,but I can´t foun it in my normal suppliers.

Could anyone give to me a tip about this problem?

Thanks in advance