Have you tried this? This worked great for me.
My suspicion is that this is a capacitor problem. If the screen is turning off every two seconds or so and then it comes back for another few, that could mean that the capacitors are not charged (or in other words, the capacitors are not able to retain the charge long enough to transfer it to the other components).
My suggestion hence, is to isolate the power board (the one that has the socket for the power input), check if any of the capacitors (the tall cylindrical structures) have bulging tops, if they do, try to replace them (Novices please bear the polarity in mind when you play with capacitors) with ones with higher rated ones (especially the voltage rating, normally these would be rated for 25 volts, so try getting one that is one step higher.TYGA
I hope this helps,
Pls Get back with your views...