Hi lanie, So glad to see new dollhouse enthusiast. I have experience in wiring I recommend you buy a tester for tape wire there Inexspensive 2 prongs with a test light you would push the prongs through the tape starting as close to plug as possible check to see were you lost power were ever that intersection of tape is you will need to re brad that intersection and move along and repeat that process as needed there is no need to remove the old brads just relocate making sure to hit both overlaping tape I think this will solve your problem however you may need a new transformer if you find that there is no power to the very first piece of tape leaving the power source.