Hi,
I'm understanding you mean the 555/BJTs circuit short-circuits.
Does the AC/DC adapter have a barrel jack adapter, by any small chance? If the circuit is "exactly" the same as last year's version, I'd get a multimeter and check the polarity of the barrel jack connector terminals or look for the little picture on the adapter sticker that shows whether outer part is +V or 0V.
It's quite common to fry things this way as unfortunately it's manufacturers' whim to use inner ring as +V or 0V - never understood why it isn't internationally obligatory for all devices to be +V inner ring and 0V outer ring on barrel jacks.