This post assumes you have some knowledge of electronics and soldering. It does not go into high detail.
Recently my PX1002 stopped charging my USB devices. It came without warning, and without any visual indication. After my iPhone went dead, about half through the day, I realized the unit was no longer charging. The 110VAC outlets continued to work just fine.
I had purchased this at Home Depot a couple years ago. They no longer stock them. At least not in the local store I checked. Thought I would try a cheap fix.
Since all 4 USB outlets did not work, that narrowed the fault down to the little Power/Charger PC Board within the plastic housing.
From the rear of the unit there are six recessed screws. Remove these and the two halves of the plastic housing easily come apart.
Locate the board and inspect the capacitors. I found no fuses so capacitors are the next common thing to fail. The type used should be slightly indented on the top of the capacitor where the X in the aluminum shows. If one or more are puffed up it is a good indicator they are blown. There are usually 2 like valued capacitors. and various others. If either or both of the 2 like ones are blown replace both of them.
The one blown on mine is C7 which is the same as C8. Their value is 1000uf 10V . These are Hi Temp Radial Electrolytic Capacitors.
Depending on where you can find them to purchase they are dirt cheap. They are in the $1.00 each range. Though you might pay up to $4.00 each and shipping on top of that. Try to find a multi-pack with free shipping.
I found a 2 pack on eBay for $3.99 with free shipping.