If it is infact a cap problem the top of the cap will be partially or fully open, it has a cross on top so it can release its guts when it gets a hit from generally external pwr spike on a new device- I say this without seeing an antminer and or could just be a faulty cap made in millions in some province in china.
If you can get clear access to the under side of where cap is located (undo some screws) get a soldering iron some solder and a solder sucker, Heat up old solder with some new solder (wire) the suck it all out with solder sucker.
Then google the part number and order online.

Caps pop for many reason internal and external, best not to draw conclusions about a companies workmanship unless you actually know what your talking about, caps resistors etc if hand/wave soldered do not always land perfectly straight and aligned. If an electronic component does make contact and works it is of course passed, electronics is not based on esthetics. Mass produced flat screen tv mobo gfx etc are made by robots and have less tolerance for components being off centre mainly due to the small amount of space they are jammed into and why they look so perfect when you open them up, I doubt antminer has robots, probably about 20 ppl all payed with half a bowl of rice and a bottle of water per day,, Jus jokin. Also caps are sometimes separated/pushed off centre when the board/s are put together to mitigate heat or allow other components to land nearby.

If cap pops again and your running off good clean pwr eg a decent pwr board not on same circuit as an aircon or heater then problem is most likely internal.

And have you contacted the supplier for an RA, you could be down for a while tho waiting or as said above they might just send you that pcb to screw in.