Hello Gil, how do you know your driver is dead? The driver never go bad unless you have salt water getting inside. You may check your transformer before making any purchase. The following action require to figure out what went bad.
1. If you have another 6000 or 6100, swap out the transformer too see if it going to work. if the transfer work fine then your driver is dead.
2. Check all the connection making sure nothing is loose
3. Give your pump a thorough cleaning
4. Last result, send your pump to your local tunze dealer and have them figure it out and pay for the part if your pump no longer covered under warranty.
If you need more help, feel free to ask.