Check the listing for details. NC1001 chassis for Smartkleen, Nitro. Condition: New. Listed at 67.00 USD. Chassis which includes the sensor wheel. Fits NC22, NC52, PT4i, PT7iEasy DIY cord replacement. Nitro is a registered trademark or trademark of Smartpool LLC in the US and/or other countries. Smartkleen is a registered trademark or trademark of Smartpool LLC in the US and/or other countries. Other names and products not mentioned above may be registered trademarks or trademarks of the respective companies. Basic pool robot diagnostics: Watch this Youtube video first: https://www.youtube.com/watch?v=hg_ABwjEiV4&feature=youtu.be Disconnect everything. Nothing plugged into anything. Undo all connections to the pump, disconnect every plug-socket also. Then do all these diagnostic testing on your work bench. We call this as dry tests. No need to assemble everything and put into your pool, not until everything confirmed good. (1) Plug the power supply to a known-good wall outlet. Turn on, then off and check if power indicator on, then off. (2) Connect the floating cord to power supply. Measure the voltage output at the other end of floating cord. That is, voltage output at the white colored plug. You may need a paper clip to access the tiny holes to get contact. It should read 30V + / - 2V. Wiggle the cord a bit and also turn the swivel back and forth to make sure you get a steady voltage reading. That eliminates possible partial continuity problem or partial short circuit problem. Then turn off power supply. (3) Put a drop of water on the pump seal which is the rubber like collar under the impeller. That allows you to dry run the impeller up to 20 sec without damage the seal. Only connect the floating cord (white colored socket) to the pump. Turn on power supply. Impeller should spin for a few seconds (under 10 seconds) and then stop. This tell if the pump is still good. As long as impeller spins, 99% chance the pump is good. Turn off the power supply. (4) With the floating cord white colored plug/socket stays connected, Connect the drive motor black colored plug-socket. Now turn on the power supply. Impeller should spin and then drive motor turns within a few seconds. Which way the drive motor turns does not matter. Drive motor is good if it can turn……… Once it turns, turn off the power supply. Don't burn the drive motor seal. (5) If test of (3) above showed impeller does not spin? Use a car battery to feed power straight to the drive motor black colored socket. You may also need paper clip. Polarity does not matter. Drive motor will turn either to right or to left if it is good. (6) Now it is pretty much clear which part need to replace, or nothing wrong. Either heat shrink the socket/plug or wrap it with electrical tape before you tug it into the pump. That prevents socket/plug connection get loose or even disconnect. Bear in mind to apply sealant lubricant on every seal when you put everything back and tighten up the nuts. DO NOT over tighten the nuts. It is plastic thread, plastic nut. NOTE: If the pump works and machine moves around in the pool, but only do forward a few ft, backward a few ft, then shut down? It is the chassis that need to replace.