Pioneer TVs, compared to other TV manufacturers, tend to be much more of a challenge to repair, and their pricing strategy for spares tend to raises questions whether they even want their TVs to be repairable at a reasonable and sane price.

However if we can get down to component repair, such as in this case, then it becomes much more affordable.
The Pioneer KRP-500P display is a solid bit of tech, though with all TVs, can go wrong. If your Pioneer KRP-500P intermittently won't turn on and gives you 8 blue standby flashes on the display (not the Media box) then we should be able to repair this fault.