hp pavilion won't turn on

[marcus1207]

hp pavilion 590p0054 shut down all of a sudden and won't turn on changed the psu  and still won't turn on with both psu how do i fix this 

[WAWood]

The support person who was the HP PSU expert is no longer around, but when he was here, he told me that the PSUs present in HP computers can not simply be replaced with regular PSUs.  So, even if the new PSU fits into the case, if it is not the same brand and model as the original, it might not work.

There are kits you can buy online to test the PSU leads to confirm they are providing the correct power.  You should look into these.

If the PSU is working properly, then the only other explanation is that the motherboard has died -- and those are not simple or cheap to replace.