Hmm... I recognize that section - it's line filters and a bridge, the square caps with the voodoo symbols are called X and Y caps - but "TH3" should be a input surge limiting thermistor. You sure it came out of that spot? How thick is it? Here's a .1μF ceramic cap for comparison -
View attachment 64104
That spot on that board, with that notation, would be for a surge-limiter. One of those is thicker than a .1μF ceramic cap. it also isn't as likely to blow the fuse the way a shorted filter cap would because it's in series with the supply rather than across it.
Can we get a shot of the back of the board? A surge-limiter will lead straight to that bridge marked D6, and the other leads to the red parallel-mode filter coil. If it's wired like that, it's definitely a surge limiter.
The bad news is this probably isn't the real problem. Check the big main filter caps, see if the tops look swollen or split. That one's easy. The other probable thing would be a blown driver somewhere.
Good news is you can replace an inrush surge limiter with a wire for a testing. Have spare fuses on hand - it's mainly there to stop the fuse from blowing from the inrush current surge when the main caps charge. Start with the power supply unplugged from the amp section, just powered alone, and see if the supply blows fuses twice in a row. First time might be surge current, second time won't.