No warranty coverage whatever then.
I'm not sure what board or component is defective that is causing the problem, but for a TV that old, not just a cleaning-out (I think I've already recommended one), but also a close inspection of all capacitors for signs of leakage or bulging of capacitors... and replacement of any such obviously defective capacitors.
The cleaning (it seems I have not mentioned it as an option before) would consist of
1. unplugging the TV from the power and all other connections, then letting it sit for an hour or two or longer, to dissipate stored charges in it, for safety.
2. opening the case, using a vacuum to clean out all dust, or wipe with a clean and only very faintly moistened rag cloth (note, do not wipe the face of the screen part, or any plastic case components, with anything other than a tiny bit of water, or they may stain or fog permanently and rather disastrously or in a very unsightly way.)
3. then, re-seat all connectors and connections, one at a time and one by one (so as not to forget how they go back together again, which can easily happen if not undone and redone one at a time.
4. see how that affects the problem. (You can inspect at the same time as cleaning, for defective capacitors, burnt components (if not obviously overheated, the reverse side of the board often shows brown spots under the component that overheated previously.)