Not much different. If its ivory or you like to tinker, you could fix it. Probably just a capacitor or coil. You can find the circuit diagrams online. If its

Not much different. If its ivory or you like to tinker, you could fix it. Probably just a capacitor or coil. You can find the circuit diagrams online. If its not or you want to spare yourself the hassle , just buy another one. You may even buy a shiny 'new' W48, albeit not cheap: https://www.manufactum.com/telephone-w48-a67326/ https://www.manufactum.com/telephone-w48-a67326/ There also is a german shop selling 'new' spare parts if you need new microphone capsules. Sorry, the website is not in English: https://telefonmanufaktur.de/73-hoer-und-sprechkapsel https://telefonmanufaktur.de/73-hoer-und-sprechkapsel