I think the problem is the power supplies have a capacitor going from one of the two AC pins to the DC neutral. This can be very helpful for increasing the power factor, but if the capacitor were to short then it would conduct one of the 240 volt legs to the negative line on the jally.
This 120 volts would not be a problem except for the fact that it goes to the ground of the USB line. Which then goes to your computer. If your computer's USB jacket is grounded, then 120 volts goes from wall through broken capacitor through jally through USB cable to computer to frame ground back to the utility. Boom.
Speaking of which, one should be able to replace this chip with an LQFP 48 pin one which would be a hell of a lot easier to solder. Recommended for followup.
C
Suppose the capacitor goes from one AC pin to the DC "ground", as you say.
Then, in Europe, you won't get 120 V there. The 230 or 240 V lines aren't symmetric to the ground. When you're lucky, the capacitor is between AC neutral and DC neutral. When unlucky, you get full 240 V there.
Another possibility might be there's a "bridge" in the PSU, halving the input voltage, and its center is connected to the output neutral... This way it could produce 120 V in 240 V environment.
The LQFP package has a little bit larger outer dimension (ends of the pins to the opposite ends). So it won't fit on the PCB pattern exactly. The pins will sit on the PCB pads, but will exceed them a bit, so they can't be soldered standard way as on their regular pads.